Uhm....angels are supposed to be made of pure energy, not flesh and blood. If he is still and angel (albeit mortal), and not human, how come he has a human body?
I'd like to refer to Dogma to answer this one. If you haven't seen it, go watch it now. Great movie!!!
So yeah, we see Tyrael willingly give up his place in Angiris council, and he falls down to Sanctuary becoming... human.
He never became human, he became mortal.
Mortal means he can die, nothing more. He is still an angel and, according to the closing cinematic, he remains mortal while he's back in heaven and he now stands as wisdom (instead of justice).
I'd like to refer to Dogma to answer this one. If you haven't seen it, go watch it now. Great movie!!!
Demon Hunter - Fadeddeath
Monk - Lumos
Witch Doctor - Nox
Wizard - Nethershade
^ This
And This^
Demon Hunter - Fadeddeath
Monk - Lumos
Witch Doctor - Nox
Wizard - Nethershade