Trying to figure out which of them is which gender kinda fried my brain for a bit.
Tagged "1other, 2boys, genderswap_(otm)"
Enkidu looks androgynous as usual while D'eon and Astolfo both look feminine
All three could be argued to be weird about gender in canon, but Astolfo is usually tagged as a boy around here so he's probably one of the boys
So, the implication appears to be that Astolfo is always a boy; one of the other two is usually nonbinary but they've been turned into a boy here; and the last one is still nonbinary
So which one is Enkidu and which one is D'eon?
Realize that Enkidu is wearing an alt outfit
Check out more of this outfit; find that at least several of the pics of it are tagged "genderswap_(otm)"
Okay, then, that means that Astolfo is 1boy, D'eon is 1other, and Enkidu is 1boy and genderswap_(otm)