I always thought it would be interesting if status effects could be combined to get a different effect, and some to even cancel out.
Two other games come to mind which use this to satisfying effect, Warframe and Guild Wars 2.
In Spiral Knights, status effects work a bit differently, it would probably fall somewhere between those two games in how it works, especially since the status and element types are quite different than in those games.
To give some ideas of possible combos, here's a list, I'm sure you guys could think of more, unless you just decide to shoot this down:
Fire + Ice = Burst. Enemy explodes, taking the full duration of fire and thaw damage, and damaging adjacent enemies.
Poison + Fire = Plague. Enemy becomes infectious, spreading a weak poison to near enemies, which can heal, but not as much.
Poison + Stun = Weaken. Enemy takes extra damage from attacks.
Shock + Ice = Magnet. Targets Influenced become drawn to each other, similar to the vortex but weaker, and will tend to bunch up.
Shock + Fire = Arc. Adjacent enemies to the target are jolted on the first spaz after Arc is applied, but not subsequent shocks.
Sleep + Ice = Stasis. Uhhh, I'm gonna just stop here, I got nothin.
Anyhow, that list is in no way comprehensive or complete or even using proper effect names, just a general idea.
Please keep all pitchforks in their appropriate hay bails, and torches unlit and safely stored away in fire proof containers. Thank you.
I don't know about guild wars, but in warframe status effects combine because you apply them to the weapon, not because you shoot the enemy with two different things and they become one. as of now, there is no way to atach more effects on a weapon.
now for the obvious "but statuses could stack on enemies without the weapons inflicting status". apart from the enormous amount of combinations there could be with our seven statuses, that have to be balanced with one another btw, it will be a programming mess to do, so I don't think it's advisable.