Well for starters let me say it like this: The wolver, crogmolisk, skelly, jelly, and even the kat lines all end up getting a armor line but what about the trojans, the construct line, gremlins, and the fiend line in general? There are all these lines that don't get enough recognition and in the end its like HQ is just throwing dead bodies away. The solution may take time but I feel that it would greatly introduce a new alternative to making spiral knights have more diversity and give newer goals to those who want a different look or to feel different. Here are my personal suggestions:

Trojan line: Similar to the guardian line but with shadow protection, the feel of having a made of stone feel. It can give Damage bonus low on swords and attack speed decrease low on the armor. For the trojan line you can get the armor and an alchamized sword just like the troika line but with that evil feel.
As for an intracit look why not make a SL armor scheme for Dark FSC? A specific looking one that gives an angelic look with lighter weight materials that give a slightly lighter appeal? Something with Damage bonus medium and no ASD?

Gremlin line: The gremlin line is always encountered and some how never manages to get an armor line? Yes we have a shield that is dedicated to the gremlin line but what about their particular look? The menders have an amazing looking head piece that would put a chaos cowl to shame. My suggestion? MAKE A HELMET! A gunning helmet with elemental protection and damage bonus low (for 2-4 stars) and an elite looking helmet piece as a 5 star helmet with Damage bonus medium and ASI low. We could also upgrade the Thwack hammers and give an alchamizable upgrade making them look usable for even a worthy sealed sword line user. Personally something with a constructive looking feel to it and a charge attack that can shoot a burst of fire making it an elemental weapon would be nice (nerfing it with normal damage could make a decent solution) Another suggestion for this line could be adding a new type of bomb that would work like a shivermist bomb where it is held out for a duration and slowly disappears but instead of going at that radius why not make a bomb that explodes at a large radius and has a status effect that gradually fades away in a ring shape instead of a circle meaning if you shield when the ring hits you you don't need to keep shielding because its attack is already passed. Gremlin technology doesn't need to be limited to hammers and wrenches so lets hear what you have to say in this perticular line?

Jelly line: Brute jellies, ice jellies, royal jellies, and even bomb jellies...Yes I will focus on the bomb jellies this time. The bomb jellies are always appearing but they get hardly any recognition as their brothers. Well instead of making a armor out of them why not make a jelly bomb? One that would deal piercing damage kind of like a shard bomb but instead of having a small radius with other little radii why not make one decent sized explosion with about 5 or 10 depending on its alchamized level? We have a large extensive amass of bombs that are more support than they are actually offence and I feel that if a bomber would like offence then they should make a bomb that makes you want to tread where you want to walk.

Owlet line: Yes they are extinct, yes they don't live anymore but why is it that the kat line roams around dead and the owlet line doesnt? I find this to be adgitating because I wana fight a bird! I'd recomend making them into shadow like enemies with a heavenly look. Maybe they can shoot feathers, or create a whole new style of enemies? Maybe a line that does both shadow and elemental or elemental and piercing? This could get a lot of thought but lets see what you guys think.

Construct line: The construct line has a bunch of cool looking monsters from lumbers all the way down to mecha knights. Though I do see a SL award for the mecha knight look why not give us a puppy look that has some benefit? Maybe against piercing? This could be interesting. And as for Lumbers why not give us a club to begin the game with instead of a sword? This could change the story line in the begining making the approach as a knight more natural.

If you read all of that I commend you *Gives cookie to all who read it* and if you have ANY EXTRA SUGGESTIONS Please feel free to think of an awesome idea.