An Alpha Roach from Lemonymous's Bots n' Bugs given the Stable prefix. Tricky to deal with.
It keeps a list of all Vek that were left alive at the end of a mission; if you leave an Alpha Firefly alive, the next Alpha Firefly to appear will receive a prefix, impacting its stats, traits, or weapon.
Some prefixes are applied deterministically; for instance, a Vek that survived and was in smoke will evolve to become Smokeproof (hence the mod's name). Furthermore, prefixes check whether they are valid for a given Vek; a Hornet can never be Leaping, for instance, since that would be redundant.
The mod has an extensive list of options, letting you disable individual prefixes and change the mod's behavior. This is also where you can read an explanation of what each prefix actually does; the mod also features tips that appear the first time you meet each prefix.
So far, the mod adds the following prefixes:
Stable, Fireproof, Smokeproof, Leaping, Armored, Massive: self-explanatory.
Heavy: +2 max HP, -2 movement.
Light: -1 max HP, +2 movement.
Volatile: explodes on death.
Undying: leaves a corpse.
Burrowing: moves by burrowing.
Ruinous: cracks its own tile on death.
Purifying: removes acid from self-tile and adjacent tiles on death.
Healing: heals adjacent Vek on death, revives corpses.
Webbing: at end of movement, web all adjacent enemies.
Splitting: at start of movement, make a small goo at the pawn's location.
Oozing: at start of movement, make a blob at the pawn's location.
Infectious: at start of movement, add mites to allies, if they already have mites they take damage.
Regenerating: at start of movement, heal 1.
Wrathful: when queueing its attack, gain boosted.
Copying: at start of movement, copies the highest tier weapon of the same type (melee/ranged) on the board, ie. a Leaper could copy a Scorpion Leader's weapon, but not a Firefly Leader's.
Cannibalistic: at start of movement, damage adjacent Vek and Cyborgs, healing 1 for each.
Spiteful: on death, fire a projectile or artillery (whichever can hit) at all mechs aligned with the Vek, dealing 1/2/3 damage depending on Vek tier.
Brood: spawn a Spider Egg on death.
Tyrannical: only applies to psions; they gain a ranged artillery that favors units.
Mirroring: Vek fires forwards and backwards.
Pushing: Vek hits push.
Groundbreaking: Vek hits crack.
Freezing: Vek hits freeze.
Venomous: Fires an instant projectile that applies A.C.I.D. before queueing its attack.
Frenzied: Deals 2 more damage, -1 max HP.
A pushing Leaper. Not a very impactful combination.
This adds no other content and only makes the game harder, but it should create interesting scenarios and work with other modded enemies.
Currently on version 1.4.1, see changelog and download it on my Github.
Bug reports, feedback, and ideas for more prefixes are welcome.