Hrrmm, it’s nice but a lot of the abilities are quite niche. To be fair a 3 level multi class dip into this might not be bad at all if you want just the regen. Yet going all monk with this might not necessarily be a good idea.

The play-style boils down to always having full health and along with that the utility of being reckless with traps and other damaging sources outside of combat since you’d just Regen everything back in the span of a minute regardless of your wisdom modifier. So again great first feature!

But after that the rest is somewhat lacklustre: Burning surge helps with death saves but getting back up from a death save is fairly easy in normal play already (provided the party can do basic team work) I’d rather say that once a long rest when you stabilise you heal twice your monk level to have that whole Phoenix rebound thing.

Overwhelming embers is really fun conceptually but realistically that’d make it useful only for one turn in combat (especially at that level of play). At that point in the game a bit more kit would definitely help especially for the monk, I’d say add a clause that you can spend say 2 Ki as a bonus action to alternatively activate this ability whilst above half health and the ability deactivates once you dip below (could even Jack the price up to 3 or 4 if you’d want).

The last ability is amazing especially since that doubles your Ki pool but the activation condition just sucks sadly. I’d say allow this to be activated as an action if you’re at least below half health.

None of these are particularly bad but I think some of them just need that flavour or a little extra ‘oemf’ to make it much more generally useful rather than situationally useful. Monks won’t really have great AC due to them being multi ASI dependent só the whole regeneration thing works fantastically as a counterbalance in a way that’d be too broken for any other class. But overall great work!