So I made a post describing what this class’d be like here: https://www.reddit.com/r/dcss/comments/1eyya94/fanmade_species_anyone_liked_the_monsters_so_much/
Right now, it works fairly well as a melee shapeshifter-focus with basically N number of extra health bars with reduced defenses. That said, player hubris 100% can cause changelings to die due to these HP bars sitting on top of your HP at the time you transform into a monster (so at 1 HP you panic transform into a bat, but the bat gets nuked and the overkill damage still hits your base HP).
What I’m struggling to figure out is how to balance the spell casting-side of things. Right now I have a new header file (crawl/crawl-ref/source/spl-mon-self-map.h at changeling_species · AlejandorLazaro/crawl · GitHub) that maps monster spells to player spells, but right now the odds of getting a monster with spells you focused on is low.
One thing I’ve considered is making monster spell books map to player spell books (which would be a LOT of mapping) or potentially having spell school + shapeshifting skill determine if any memorized spells port over while you’re in a new monster form.
Thoughts?