Looks very nice!
It would be great to see late Atlantis get some more love... The assassins you've made look quite nice, but the tupilak rider is pretty worthless. It wouldn't really be thematic to make him buffer, but since he rides a tupilak maybe he should get huge mapmove? That would make him waaaay better... (he'd also need flying, maybe stealth? Maybe also let the tupilak fight?)
Hey, I like these ideas...
Maybe they could also get the Caelian who taught them how to iceforge?