Nidus has a well-rounded kit that allows him to fill multiple roles throughout various content. Unfortunately his entire kit heavily relies on specific ability interactions with so replacing any ability can significantly change his playstyle. We choose to not run a subsumed ability on this build but if you're willing to take the time to learn each different playstyle, you can make use of any number of abilities.

Empower and Fire Blast are abilities that can apply to general content. Larva is replaced unless you're planning on using its new buff, then you'd replace Virulence.

Terrify and Pillage usually need an insane amount of Strength to strip armor and shields but due to the way Parasitic Link increases ability strength they can also work on this build.

[Abundant Mutation] and [Insatiable] combine to give [Nidus] a massive reservoir of stacks to use offensively or defensively. Realize that you lose all of your stacks when you're downed so be careful fighting extremely high level enemies.

Strength is pumped higher by sacrificing Efficiency and a bit of Duration. Virulence will keep your energy bar topped off when used correctly so this shouldn't be an issue in most content. [Transient Fortitude] can be replaced with [Intensify] or [Energy Conversion] if you want to have a bit more Duration.

Range is given a small boost to make his abilities a bit more manageable but you can replace [Stretch] with any other mod that you see fit on smaller tilesets.

[Vitality] can be replaced with [Rolling Guard] on extremely high level content. Without shields, you'll have to time your rolls perfectly.

Arcane [Guardian] gives you a significant EHP boost but can be replaced with any arcane to suit your playstyle.