Night koloss+reincarnation seems to trigger an increase in maxhp

night koloss+reincarnation seems to trigger an increase in maxhp.
I go from about 1400-2500-4200 maxhp after a first and then second casting of reincarnation.

either big boned is triggering from casting reincarnation, which would be a bug, OR this is an intended feature of reincarnation that I wasn’t aware of and everything is fine.

for testing purposes I made another creature this time a forsaken swampdweller, and when casting reincarnation on it, maxhp goes from about 3000 to about 5000, so maybe this is just an effect that isn’t a bug and is supposed to work? either that or it’s a bug with both traits.

edit: I just realized this is probably not a bug, why? because the spell clayman is essentially 100% as effective as my combo! So this convoluted combo just saves the clayman step, but adds different alternate extra steps of it’s own anyways.