From my opinion, he may be sura because there's a lot of hints and mentions.
YOOOOOO
now that you mention it THEY DO SEEM SIMILAR
If they similar at all maybe they similar with doing something good with mujin too ahahaha jk ┑(￣Д ￣)┍
I think choa really is sura because everywhere he goes he bring destruction and i think that the destruction that is being mention is mujin. When choa bring mujin back to their doctors base, its like hes bringing the destruction on their house causing all of the other doctor to die. But its just my theory
I dont know but the story of that red haired guy is similar to mujin and choas story. Choa save mujin and mujin became obsessed to him just like what happen with that red haired its like a cycle. But is mujin really sura or choa?