Thanks for all the great feedback, everyone. Cheers, SilentRoamer and Garet Jax. In answer to various questions:
Ashtinahgma: Real sword, enhanced with sorcery, like the Nonman in TDTCB prologue whose sword seemed to reflect the light of another sun kinda thing.
Hirtius/Pansa: Yes, just ritual-esque paint on the face. I don't know if I meant it to be THE Copper Tree, but I see the correlation now. I more had in mind the connection that witches seem to have to nature in Earwa. The golden color was just an attempt to make it stand out against the background colors. So, unintentionally intentional.
Triskele: I agree. I don't think Su'juroit will feature again, but a showdown between Kellhus and the Witch-King would be awesome.
Curethan: You wouldn't believe how many times I went back and forth with the eye-glow/no-eye-glow thing. Wilshire's defense on my part is accurate, and his example was exactly the one I was going to give. The portrait is in that moment after the sorcery has been called. That's where I ended up going because I wanted to show the face and eyes.
Wilshire: Back to the face comment, thanks! That's what I was trying to go for. The inhumanness of Nonmen features, which is why I decided against the eye-glow. Tried to show the 'beauty' of their faces, the differences between Man and Nonman. Also, for this one specifically, I wanted to make the face androgynous. Su'juroit's title is the Witch-King (female-male monikers), so he/she could have been either in my mind.
Anyway, thanks for listening! Cheers.
Screenshot of eye-glow version below.