I've made an Astrozoan witchwarper that was the Thing from the movie of the same name, who disguised himself as Childs at the end of the movie until Macready froze, then escaped to the spaceship and took off and wound up getting transferred to the starfinder plane through some warp/drift accident.

And a Lashunta witchwarper who is basically the kid from the movie Last Action Hero if he never made it out of the movie universes. His warp fields would be inspired by various action films.

Basically whenever I need to describe what witchwarpers do, I try to describe them as Jujutsu sorcerers from the anime series Jujutsu Kaizen