headcanon time!
oli still has some features from his origins, although he still looks mostly human
for example, water still stings him, not enough to hurt but enough to be an annoyance (enderian)
contrary to that, he can still somewhat breathe underwater (atling)
a small part of his skin is wood, though its not very noticeable (forestborn)
every now and then when he gets hit my a mob or player theyll get hurt instead (thornling)
the cold doesn't really bother him too much (iceling)
sometimes he gets a craving for blood, and he also has paler skin (vampire)
he has wings, though they're translucent and he cant really fly with them (fairyborn)