@talonair From what little we've seen, the angelic and abomination forms are derived from the related demons and beasts - an Infernal gone angel will look different from a blood divine, for example. Further, we've seen the Nhee gone abomination in art work - it a bear with giant horns, bigger teeth and claws, and turned blood red. Admittedly, it's not an official thing, but it's a general hint, I would think.
so, that's some idea about what these transformations will be like - you'll still look vaguely like "you" but with the demonic stuff stripped out and replaced with heavenly set - bright auras, feather/halos, ancient rune masks of power, etc. XD
I will remind those who have never done a deep dive on the old testament - 90% of all angels look freakishly weird in various ways, so making a significant guess on what an any of the three angels will look like, other than humanoid because the game runs on that for player characters, is pretty shot in the dark.