This is a zero forma build for [Nidus] that will allow you to use the power of the Infested for good. [Nidus] is a sturdy caster built around his Mutation passive. Gameplay is simple: hit enemies with his 1. A lot. His 2 can scoop up enemies into a neat pile so you can hit multiple at once (potentially refunding the energy cost, or even gaining energy if you hit enough). His 3 costs a little Mutation, but gives you great survivability when you cast it on an enemy (you can cast it on an ally to give them power strength, but that's rarely worth it). His 4 creates a zone of infestation that will heal you and, because of the [Insatiable] augment, give you additional Mutation stacks for hitting enemies with your 1. All in all, [Nidus] has a very strong and cohesive kit. My only complaint is that it can be a little slow to get going, and a lot of missions are going to be over by the time your damage is starting to really ramp up. For that reason, I tend to prefer [Nidus] in endless modes like Survival, so you can use him at full power for longer.

If you like [Nidus] and want an endgame build for him, I have one here.