This is perhaps one of the best ideas for SK I've ever herd!
The idea I like the most is the Howlitzer set, it sounds epic!
Devs need to take a look at this.
/Clap Verodius

It appears that the Howlitzer set is within the same boundaries of the ridiculously powerful Divine set. I think it needs a little more.
Perhaps some bonus to handguns?

The more - the merrier! Anypony recalls Arkus?

Our current variety of enemy mechanics have been chained to the ceiling and headbutted far too many times to even consider them difficult; particle/animation lag is our greatest threat, the enemies themselves can be easily dispatched alone.

Why would they spawn in status stratums when it would be more community reliant to only allow them in their respective family based stratums? Of all the potential stratums (the four statusesuses, the six families, total of ten) they would have a one fifth probability to appear in a randomized gate. Allowing them in any status stratum would bump that rate up to two fifths of the time; almost every other randomized stratum would have a miniboss.

For the icon and arena replanning, yes; it would make arenas more threatening to the average user. However, for some the last massive wave of enemies is threatening enough. Unless the existing arena waves are changed, this would mean having two potential arena floors; we want these to be somewhat rare to encourage impatient users to burn energy to encounter them, not have a new boss to farm whenever they want. If we did have a new pattern of spawn waves for arenas in a secondary style, it would mean having a difficulty based arena rather than a Pikmin style spawn pattern; our current arenas just throw enemies at you constantly, like Pikmin rapidly attacking ceaselessly until defeat or ants attacking a somewhat larger spider than the individual ant. There are one to four of you and a couple dozen of them. The problem with this is a lack of thought based difficulty, rather picking them off or going for area of effect coverage. All you need is a Brandish/Divine Avenger/Vaporizer/Nitronome and that crowd of twenty or so is gone. However, does this mean to have an arena of just a few Trojans at a time? No, that would be stupid and annoying at the same time; Trojans can be outsmarted somewhat easily, though after three at once it goes from taking a little while to being there an hour for stupid reasons/raisins if you are soloing. If we had a second area it would have walled rooms instead of floating platforms to make use of Alchemers to encourage the community to use them again, seeing as everyone and their sister use a Polaris to spam everything everywhere forever and it annoys everyone else. Mobile bombers especially.

For the combat mechanics:

Jelbug

For a giant bug, it certainly is a giant bug; make it a little smaller so no one whines about it eating a real boss even though it is a miniboss. They are supposed to be less threatening/difficult, not eat their superiors. No matter how amusing it would be to see a giant bug eat Snarbolax. At least now it makes sense why you wanted status stratums to have them, to make them specialized; the problem with this is having a status variation of all four when they are supposed to be special. A while ago we had a Lichen for every status jelly, Toxilargo being the sole survivor of balance.

For your T3 exclusive attack on this miniboss, keep in mind this enemy concept has a spherical form it may take; use this to your advantage. "What do you mean?" Make it roll. Outside your hopping attack of creating spikes and what not, the Jelbug can curl up into a sphere and roll around the map similar to how Alchemer bullets bounce; the Jelbug curls up as it would for the other attack, but instead begins the imminent attack animation (the glow on the floor) in the direction of where it will roll, then proceeds to roll straight until it bumps into something in which case it bounces off and continues in the ricochet direction. If ran over, knight and enemy alike are inflicted with a 4/3 (good chance of moderate) stun. For this boss there could be certain objects which when bumped into cause the Jelbug itself to be incapacitated, uncurling and laying exposed for several seconds. This would be similar to how the bells work on beast family enemies but is not manually triggered. "Would this just be a more annoying Trojan charge?" No, while rolling it can be shield bumped to change its direction as shield bumping an enemy regularly causes it to bounce in direction of the path of reflection. That did not rhyme intentionally. It would turn an arena into a pinball arcade game without tilting.

Crimson Overseer

Yes. This is what all silly concepts strive for. A gremlin riding a giant robot which looks like something mountable to begin with. Why is the rider using a lance when they have science on their side? What are they, Devilites? No, get one of those rocketeer gremlins on there. When the giant Scuttlebot dies the rocketeer becomes active in combat to give users without the expansion pack a preview of how silly they are. The rocketeer can fire while mounted, though only if the giant Scuttlebot is not moving because firing a rocket launcher while moving is not convenient. The Scuttlebot itself should have two attacks: the regular three bullet shot, though larger bullets, and a laser. The bullets are obviously larger than regular Scuttlebot bullets, but the laser can vary by tier; T1 has a Retrode beam which simply fires as a projectile and does not linger, T2 is faster and goes a few spaces farther and lasts a few seconds, T3 can have a Roarmulus continous laser of death. This is for when it goes in the center while invulnerable; the T1 laser repetitively spits, the T2 laser is faster and covers a wider radius, the T3 laser forces knights to get out of the way. Giving the rider gremlin bombs would just annoy sword users when the shields annoy them to begin with. In each tier the attack and movement speed increases for the Scuttlebot as normal.

Cerberite

Cerberus, I see what you did there. Each of its heads are most likely Howlitzers, though giving each head the same mechanic as the tier it is in may prove obnoxious in T3; make it happen. The T1 Cerberite heads each fires one bullet at a time for the ranged attack, T2 each head fires three, T3 each head fires six. The tiny ghost snots, invulnerable temporarily? I hope there are at least places to hide, seeing as they detonate upon contact. The melee attack may as well be the Snarbolax biting attack but with two bites per head; at first it does six, then when its health drops there is less attacks to avoid.

For the rewards:

I am going to nail you on the weapon mechanics; nail you to my wall. Not the wall in my room, there is no room there. You would probably look nice above the fireplace, though. Stop squirming.

Keep in mind my primary activity around here is using a rubber chicken to slap weapon concepts into shape; the coach who never lets you take a break when you only ran two miles or did less than a hundred push ups. There is no crying in baseball.

I will demand exact/relative values ("a lot of element defense" is not valid; "# bars of element defense" is):

For swords:
Basic attacks:
Swing radius (Calibur/Brandish is one space in a 60 degree angle), swing speed (Calibur/Brandish, Cutter, Troika, etc.), swing combo (two swings per basic combo, etc.), swing angle (Calibur/Brandish is 60, Troika is about 120), extra effects (any status, specialized damage type(s), attacks cause projectiles to fire, etc.), damage rates (base this on a neutral target as specialized damage bonuses are not consistent with every weapon; the last swing is always more than the previous swing(s)).
Charge attacks:
Area of effect (if there is more than one damaging part of the charge, describe all parts and their respective areas of effect in damage and
specific details of the mechanic; this is basically the swing radius and angle), animation speed (Troika charge is somewhat slow, Brandish charge is fairly quick), movement speed while charging (most swords are fairly even).

For guns:
Basic attacks:
Exact/relative bullet speed rates ("slow boolits" is not valid; "the same bullet speed as {gun} is), bullets per clip (Antigua has six, Magnus has two), mobility (Autogun and Magnus do not let the user move while firing, Alchemers do), bullet path (travels # spaces before the bullet dissipates), extra effects (damage type, status if applicable, bullets bounce [Alchemer], bullets cause something to happen [Catalyzer mine detonation], etc.; why this gun is special), damage type (based on a neutral target).
Charge attacks:
Bullet speed, bullets fired in the charge attack and their damage rates,

For bombs:
There is no basic attack anymore so skip to the charge:
Blast radius (Nitronome is four, Big Angry is three), approximate fuse speed (Nitronome has a fast fuse, Big Angry has a slow fuse), base charge time (no charge bonuses; the standard for most weapons on base charge rate is five seconds), damage rate (base this on a neutral target; for bombs I will nail you on balancing more than guns and swords), movement speed while charging (Nitronome is fast, Big Angry is slow), any extra effects (statusesuses).

For statusesuses use the following "table":

Possibility to afflict:
Slight
Fair
Moderate
Good

Degree of affliction:
Weak
Minor
Moderate
Strong

1 = Slight/Weak
2 = Fair/Minor
3 = Moderate/Moderate
4 = Good/Strong

Ex:
Good chance of moderate {status} = 4/3 rate of {status}

Slight chance of weak {status} = 1/1 rate of {status}

It is not a ratio (2/3 does not equal two of three probability) as a fraction.

With this in mind and foot, prepare for science.

Bio Cannon

A shotgun has already been attempted; Autogun has several bullets per shot covered with balance, Valiance has close range knockback covered. This appears to simply plop explosive blobs of jelly at fairly short range; it has been discussed before and defeated because it would prove unuseful at close range when the user would still be within blast range of their own explosives, making it a gun-bomb more than appropriate, or be spammable and essentially be the basic attack bombs used to have.

Jelbug Shield

I am going to be as straightforward as possible for this: make it for bombers. The enemy it is based on essentially uses bomb related attacks (explosive blobs, spikes in the somewhat circular area). It does not fire projectiles, sneak up on knights to attack, or have significant movement speed; it hops to create quakes as a bomb rapidly planted attacks. Gaining bonuses in exchange for the defense a shield would normally have was well played, though.

Prism Bomb

This is either an overpowered combination of Dark Retribution with Nitronome or playing pinball with enemies; either way, specific damage rates and areas of effect determine whether the mechanic is overpowered. Beep boop.

Kontarion

Every time someone tries to make a lance/spear mechanic they either copy the Flourish mechanic or steal how Slag Guards work, which are both similar in a way. Heavy swords should not have three hits in the basic combo. The hammer is an exception. Lances were not used as our heavy swords work, but polearms do. I had previously planned to work on a mechanic for polearms and spear weapons but they would either outclass the heavy mechanic, be part of the heavy mechanic, or be stupid. The Slag Guard mechanic would essentially be an overpowered version of the Flourish line, and we all know how people feel about how it already works.

Howlitzer set

For being based on an enemy weak to element, it sure has defense against element; derp. I know we already have split shadow-normal on two sets, Snarbolax (more normal than shadow) and Skelly (more shadow than normal), but keep in mind what it is based on: a turret. Considering most projectiles, enemy and player created alike, are not normal damage and turrets are easily taken down by guns it makes less sense to be resistant to what should be its downfall. Keep in mind giving charge time reduction buffs to equipment means significantly reduced defensive ability, possibly meaning having only shadow damage and no second defense type; it would be crippled defensively, but would make it the blitzkrieg gunner set sought by the veteran gunslingers; sacrifice defense, get more offensive buffs.

As for the "special" rewards from the minibosses and how to obtain the miniboss weapons, keep in mind there are many users who have stocked several hundred of each of the three regular tokens. If they were given the same direct token reward system as existing bosses have they would just be new bosses, not that there is a problem with that necessarily; except where they are not guaranteed to appear in a gate. By using existing tokens to obtain the equipment veterans would just pump their giant pool into Brinks to get everything instantly, but a new token system would force users to actually play through a few times to get the new content.

Looking back over this post, I am amazed how much I can write up without hardcore effort; I just let my thoughts ooze out of my eyeballs and all of this happens. I rarely go back and edit, aside from the occasional typo and/or incorrectly placed word (hats and buckets are not the same thing). Where is this oozing when I need it?

My reaction to this thread in general:
http://cdn.memegenerator.net/instances/400x/21152823.jpg

Levels
I feel like these guys actually deserve have a little more of a thematic touch to their levels, similar to Briar Bone Barrage for the Toxilargo. Jelbugs could have a forest-like level whose appearance takes after the Gloaming Wildwoods. Crimson Overseers could have a sort of abandoned depot level similar to those of the new Rescue Camp missions. Cerberites could reside in levels styled like a soldier's graveyard.

According to the file name on the wiki, this icon is for minibosses, and it's used for Briar Bone Barrage (Toxilargo) and Stygian Steeds (Trojans). If the minibosses you've suggested resided in more thematic levels, I feel like this icon might as well represent them.

Jelbug: appearance/mechanics
The Jelbug sounds very interesting. As far as I can remember there haven't been any decent insect enemy ideas (spiders are not insects). Regarding the appearance of the forelimbs, I assume you mean something like this? This could make for special attack for Tier 3 version: a simple grab and bite using said forelimbs and its mouth (respectively). The problem with this is that a grab/bite would cross over into the standard jab/swing attack, so perhaps the swings in T3 could be changed to grabs instead?

You already listed one issue I have with rolling as an additional attack, and that's that it's (yo whatup, grammar?) similar to bouncing. Given the choice between the two, I would say rolling suits insect behavior more than bouncing does, but that isn't really a valid argument - Electrolisks are lizards that spit high-voltage goop, and slimes produce solid spikes underground (okayface.jpg) - so I'll disregard it. The other issue I have specifically addresses Luguiru's suggestion, and it's that existing ricochet behavior would make this roll attack highly unpredictable, likely resulting in rage similar to that produced by ninja attacks from Slag Guards. That said, it probably shouldn't be terribly difficult to program a realistic ricochet, making Luguiru's rolling suggestion a favorable one.

Crimson Overseer: appearance/mechanics
I must say, I liked your Gremlin War Walker idea a little more than the Crimson Overseer, but this one has its merits. For one, it seems a little more feasible both in terms of mechanics and appearance (still haven't gotten around to making a War Walker model in Spiral-Spy, sorry). Unfortunately, my unimaginative brain wants me to tell you that "a bite from the Scuttlebot" seems a little strange.

The aforementioned unimaginative brain also wants me to tell you that (as Luguiru said) lances don't seem to fit with Gremlins' existing weapon themes, even if they look like this. However, I think it makes even less sense for them to have mortars - these guys are supposedly meant to keep gremlin workers in line, so why not give them something to goad said workers. Something like a whip, perhaps?

I think my only other issue with the idea is that the Tier 3 special attack would indubitably reduce my already-bad framerate to a nonexistent one.

Cerberite: appearance/mechanics
Heads: One way to differentiate them from Howlitzer heads could be just making it so they don't explode upon destruction.
Spirits: Are these things going to have some kind of targeting mechanic at all? For example, if a knight walks within a range (say 30º) of the current direction of spirits' "walking", will the spirits begin to chase said knight? As for detonation, it would probably be okay for them to just directly take after the lost spirits.

Equipment
I won't pretend to have the patience of Luguiru when it comes to hammering out equipment mechanics. I'll leave you two to decide on exact damage outputs. You may with to specify in the OP that your damage numbers for the Bio Cannon are for the 5* version (assuming they are).

Most of the ideas seem alright to me except for the lances, and Luguiru's already covered what I would have said. In line with my suggestion that Crimson Overseers have whips, said whips might as well take the place of the Kontarion series as token rewards.

Final notes
Thank you for putting so much time and effort into this thread. Good stuff.
Since you said the miniboss levels would appear before terminals and subtowns, would it be safe to make the assumption that they would be Arcade-only?

I have not checked recently if they still exist, but have you seen the "miniboss" stratum images? I forget what the two floors before it are, but the floor image itself looks like a little Gun Puppy with sharp teeth. In the fiend one they had a bunch of trojans, in a jelly one they had Toxilargo. They gave decent payouts but were not too common and only seemed to appear in T3. If they removed it, reimplementing it with these new bosses ought to kick start Arcade runs again for a while.

For the Overseer, I read it as the gremlin demo bombs; in T3 they are horribly obnoxious at close range. It makes more sense to have the Roarmulus style aerial missiles but with slightly less area of effect; I have not done Roarmulus in a while, though my memory says the aerial missiles had a radius of three, about four or five are fired at once, and they took approximately three seconds to detonate upon the blast range becoming visible.

What do you mean by making the Howlitzer heads less effective? Less bullets? Less damage? Less down payment until 2014?

When it makes the little snots I imagine about a third of the room flooded with them like in the old mission they are currently in. Depending on how many of these are vomited and the size of the battle room would determine whether this is fair or obnoxious.

Yes, but Howlitzers are fairly offensive turrets; their head still wants to kill you even after it dies. None of the equipment we have has a pure non-normal defense, I thought it would be interesting to offer something more offense based than the Chaos set and its +2 universal damage and charge. I suppose the real question is whether the defense types for enemy based sets are also based on the enemy or based on how it is supposed to be used. Most sets have split normal defense to protect against melee attacks, though as we all know turrets can be outmaneouvered at close range while the turret takes a few seconds of immobility to fire. Most guns are element, and turrets can be counter fired by long range projectiles against their own. The most pierce weapons are in swords with the three Flourish lines and Snarble Barb line. This could be heavily debated; giving it pierce defense would counter the kamikaze head explosion upon contact, but giving it element defense would mean countering the majority of commonly used swords (Brandishes, Seerus hammers, Divine Avenger). If you feel colorful it could have a little of both pierce and element and keep its shadow somewhat decent.

The following may cause inflation.

At Brinks users can exchange tokens for items (materials, trinkets, equipment). A 5* trinket sells to an NPC for 10kCr. A 5* trinket costs a hundred of the classic tokens (Forge, Grim, Primal) and is bound upon exchange with Brinks. There are NPCs in the Bazaar to exchange these trinkets for 10kCr. For the 5* trinkets a damage defense trinket gives about two and a half bars against a specialized defense and the status trinkets give about two bars of defense against a single status.

Silvermail is only the armor, there is no helmet or shield to go with it; there may be something in the future, but until then it is not a set. Unless I was typing with my feet I believe I stated most sets have split normal defense.

As a gunner-keep-your-distance sort of armor it would be sensible to give it another specialized defense instead of normal, but element would not suit the Howlitzer based equipment. With split element-shadow it would imitate Divine, but with split pierce-shadow it would imitate Silvermail; or compensate with having a little of both pierce and element while retaining shadow for a somewhat decent set all around except against normal, in which case you get nailed by melee attacks. I understand what you mean by elemental damage being dealt through projectiles often, but refer back to what it is based on; Howlitzers are fairly offensive based, even when they die they still want to attack. If I were you I would just make it all shadow and keep that lone defense somewhat high to compensate for the lack of split defense types, but if you want to split it then by all means do so.

I am now a bucket of thumbs.

Be very careful using that word to describe a weapon.

Keep in mind the equipment is supposed to be useful for various scenarios. It can still be favored in a few over others, but do not isolate it.

Do not abuse edit-bumping, it annoys people who notice it; like me.