Xenocidist

You are ever wary for the abominations of change, seeking to purge the gene pool of genetic deviants, misshapen mutants, and all manner of corrupted freaks.

Favored Enemy

In order to select this ranger archetype, you may only choose from the following list of favored enemies: aberrations, fiends, monstrosities, or oozes. If you already have another type of favored enemy, you must replace it with a type from this list.

Once you have chosen this archetype at 3rd level you always apply your favored enemy feature against creatures currently using a polymorph effect, possessing the mana-wasted template, or any template with “half-” in its name.

In addition, starting at 7th level when you hit one of your favored enemies with a weapon attack, you deal 1d6 additional damage. At 11th and 15th level this additional damage increases by 1d6 (to a maximum of 3d6).

Your favored enemy feature otherwise functions as normal.

Crowd Control

Starting when you choose this archetype at 3rd level, you gain proficiency in Persuasion and Performance. You gain a bonus equal to your Wisdom modifier when making Charisma (Persuasion or Intimidation) checks to influence the behavior of a crowd.

Xenocidal Hunter

Also at 3rd level, you gain the following two features: Devolution. Whenever you score a critical hit against a creature using a polymorph effect, as an immediate action you can attempt to suppress that effect, forcing the target to make a Wisdom saving throw (DC 8 + your proficiency bonus + your Wisdom modifier). On a failure, any polymorph effects on the target immediately cease.

Taint-Sniffer. You have advantage on scent-based Wisdom (Perception) checks, but only to sense your favored enemies (including polymorphed and templated creatures listed under the favored enemy feature above).

Genetic Purity

Beginning at 7th level, you are immune to polymorph effects. You may spend your reaction to allow a polymorph effect to affect you.

The following archetypes present excellent options for a variety of iconic roles and character types related to dealing with mutants and mutations, whether genetic manipulators mutating their test subjects in an endless variety of horror or zealous crusaders devoted to rooting out and expunging all traces of the mutant stain.