Nidus/Abilities

Adaptive Mutation
The Infestation dwelling within Nidus mutates rapidly when used against his foes, fueling his abilities and yielding various symbiotic benefits. Nidus possesses various passive mechanics highlighted in the tabs below:


 * -|Mutation/Adaptation Stacks =

Mutation/Adaptation Stacks is a resource unique to Nidus, indicated by its counter and gauge displayed in the lower-right on the HUD, above the ability icons. If Nidus is killed with at least 10 Mutation/Adaptation Stacks, those 10 stacks are consumed, granting him 5 seconds of invulnerability and restoring health to 50%.
 * Note: the game refers to this resource as either Mutation (passive ability description) or Adaptation Stacks (ability cost), yet they refer to the same thing.
 * The gauge is divided into 5 sections which represent the number of hits dealt to enemies via abilities. The counter keeps track of the number of stacks.
 * Upon damaging one or more enemies for a total of 5 times via Virulence or Ravenous, the sections of the gauge light up clockwise and become unlit again on a complete cycle, while the counter increases by 1 stack. Stacks are retained until used by Nidus.
 * Up to a maximum of 100 stacks can be attained. Each stack causes the gauge to gradually appear more infested. Upon reaching 100 stacks, the counter is hidden and the gauge is overlapped by Virulence's ability icon colored in red and black.
 * Parasitic Link costs 1 stack to activate instead of using energy.
 * Ravenous costs 3 stacks to activate instead of using energy.
 * Nidus' appearance changes as more stacks are collected:
 * At 3 stacks, tendrils will protrude from his neck and upper spine, while the carapace around his ribs will open.
 * At 5 and 7 stacks respectively, the carapace around his thighs and arms will open to reveal more infested flesh and tendrils beneath.
 * At 10 stacks, the carapace on his helmet (including default and alternate) will open up, and many more tendrils will be exposed.
 * When stacks fall below the required triggers, Nidus' appearance will revert to the appropriate stage.
 * -| Undying =
 * A UI banner displaying "Undying" and an invulnerability timer will appear at the top-center of the screen while this passive is activated. The required amount of Mutation/Adaptation Stacks will be visibly subtracted from the counter and gauge.
 * If Nidus has less than 10 Mutation stacks, all stacks will be consumed without benefit if he is downed or killed.

Nidus gains the following additional bonus stats while leveling up, alongside regular statistic increases for his health and power pools indicated at the top-left of the Warframe Upgrade page:
 * -|Rank & Stack Bonuses =
 * +?% Armor (+50% at max rank)
 * +? Health regen per second (+13 at max rank)
 * +?% Power Strength (+15% at max rank)

As Nidus collects Mutation/Adaptation Stacks, he also gains several bonuses based on stacks accumulated:
 * Armor Bonus: Armor increases by 50 for each of the first 5 stacks, to a max of 250. Unknown if affected by armor mods.
 * Health Regen Bonus: Health regeneration per second increases by 1 for every 3 stacks up to 7 health regen per second.
 * Sprint Speed Bonus: Sprint speed increases by 0.01 for every 1 stack up to 0.10 additional sprint speed.