I've seen this thread come and go a few times, each time it wasn't really done well and not much effort was put into making it both appealing and easy to follow. I'm going to attempt to do both:
Weapons gain "Accessory" slots just like armor does. Certain weapons do not have certain slots, just like how some armors cannot have certain accessories. Accessories are destroyed upon removal, just like on armor.
__________[SWORD SLOTS]__________
===AURA SLOT===
This one is pretty self-explanatory.
Weapons with this slot: WRH, Suda, BTB, FF, FFlame, FRiga, WHB, Ach, CIV, Sciss/Levi, WMill, Cautery.
Weapons lacking this slot: FoV, Triglav, GF, DA, DVS, Voltedge, Glacius, Combuster, LHB
Flame Aura
This could possibly cross over with the armor accessory. Gives your weapon a burning aura.
Toxic Aura
Gives your weapon a venomous aura
Divine Aura
Identical shine for the one on the Skolver coat
Twinkle Aura
This could possibly cross over with the armor accessory. Gives your weapon sparklez
Status Trail Aura
Causes a Weapon Trail to shimmer behind the swings.
If the weapon inflicts a status, a trail of status coloured light will beam out from behind wherever the weapon is moving. If the weapon does not have a status, the trail will be a bright white or red if the weapon is normal damage, green if elemental, yellow if piercing and purple if shadow.
Prismatic Trail Aura
A continuation of the previous aura, this causes the status trail to become colored in your personal color.
===PIECE SLOT===
This would alter a certain piece of each sword, depending on what type of sword it is, or tack something new on, depending on the accessory. This will probably require a lot of models, but if I look into it more, pieces might be able to be recycled between swords.
Weapons with this slot: ???
Weapons lacking this slot: ???
Hilt Mod
This would swap the current hilt of the weapon out for a secondary hilt (For swords that are just one piece, the hilt would be pasted over the top of the current hilt)
Weapon Crest
Similar to the Rank/Monster Crests that are appliable to armor, those little shieldy icons can be added to your swords too. Doesn't matter if they get a little floaty, they're magnetic/antigravity powered anyway, or something.
===ANIMATION SLOT===
This one is probably going to require the most work to work into the game, due to the amount of stuff that they alter.
Sheath Mod
A sword with this accessory will appear on the player's back when in non-combat areas. Of course, as discussed in another thread, resizing and repositioning will need to be altered on a per-weapon basis.
Charge Mod
Alters the charge attack animation. I'll be going through the different charge animations soon...
Attack Mod
Alters the basic attack animation. Base attack animations (these aren't the upgrades, they're my notes on what attacks exist, and later I'll be adding what the animations become if this accessory is attached)
BALANCED: Left swing, Right Swing, then a wide swing to the left with the knight's right foot far forward.
WEIGHTED: Wide right swing, then a spin followed by another wide right swing.
===TEXTURE SLOT===
These accessories change the texture (duh!)
Polished Metal
Possibly could come with the Twinkle aura. What this does is another light calculation pass over the sword, increasing how bright it is. Might look crap, and might not even be feasible in the code, but I saw it in Spiral Spy and it looked interesting. Will post images later.
Battle-worn
Not so much a recolour, it's more of a texture overlay. Damage, scuff and wear marks are overlayed onto the armor, like the scratches on some of the Aegis shield reskins.
Paint
Mucking around in Spiral-Spy at the moment and seeing if I can recolour weapons to match armor themes...
__________[GUN SLOTS]__________
===EFFECT SLOT===
This will add miscellaneous special effects to a gun.
Compatible Guns: Calla, Slug, Tenz, AP, Nova (correct me if this gun has an aura thingy), Blitz, Valiance
Incompatible Guns: Polaris, Supernova, Bio, Neut, Umbra, Storm, Hail, Magma, VPB, Plague
Smoking Muzzle
A trail of smoke will rise from the barrel of the gun, identical to the Volcanic Pepperbox
===ANIMATION SLOT===
Charge Mod
Alters the charge attack animation. I'll be going through the different charge animations soon...
Attack Mod
Alters the basic attack animation. Base attack animations (these aren't the upgrades, they're my notes on what attacks exist, and later I'll be adding what the animations become if this accessory is attached)
LIGHT: Gun held straight out and a small recoil is felt each time a shot is fired. The gun is spun around the finger in the trigger-guard to reload.
__________[BOMB SLOTS]__________
===TEXTURE SLOT===
Alters the texture of the blast.
Compatible Bombs: ITD, BAB, Nitro, HDC
Incompatible Bombs: DR?, DBB, All Shard Variants, All Haze Variants, All Vortex Variants
Colored Thermite
The blast is changed colour to match the chosen colour. Colours come in all the variants that personal colours can be obtained in. (F*** off, Google Chrome, I can spell "colour" however I want)
ITD's Bolt Washer, HDC's Casing and Key paint, BAB's face and Nitro's glow change colour to reflect what colour has been attached.
Prismatic Thermite
Identical to Colored Thermite, except that the bomb's colour changes to match it's owner's personal colour.
===AUDIO SLOT===
Alters the SFX of the blast
Retro
Blips, beeps and whirs Game-And-Watch style
There are so many more I want to put here lol, like passing wind and other trolling sound effects but i think I'll just be quiet and see if anyone has any suggestions for this. XD
__________[UNIVERSAL WEAPON SLOTS]__________
===TEXT SLOT===
Name/Description Mod
Allows you to customize your weapon's text. The name/description is entered when the accessory is installed, after which the name/description cannot be changed. Destroying the accessory returns the weapon to its original name and description. You may choose to change both, or change one and leave the other as the default.
How will we obtain these you ask? Tempered Steel Lockboxes. These lockboxes function very similar to Mirrored and Iron lockboxes, apart from the fact that they only contain Weapon Accessories. Text Slot mods will be the most common, followed by Pieces, then Auras, then Animations. Throw in a few UV tickets at random chance with each Steel Lockbox opening.
Yes. Except the attack mod. And the fact that I can't make my Combuster all sparkly, like a vampire :P