Two have stupidly high drain (VS/EMP). But VS goes for your resist, regen and mass drain (from range). EMP is more a major drainer weapon (close range). (it can deal it’s drain in damage but that’s only if you can get your opponent drained before hitting them with it).
Bunker is like a malice (in drain) deals massive damage if drained (or with luck).
If your mech can handle all three. It’d be a formidable build