To me Yuu not being able to OB is very tragic. Bc OBs in the books are emotional climaxes, not just overdose of magic. It ties magic and emotional hardship together, and makes trauma a visible thing. OB victims risk dying from it, their own emotions, it's another metaphor.
Spent a lot of time staring at this artwork (i swear im normal) so i noticed a few things:
-he's wearing a different style of earring
-his shoulder guards have scratches & looks battered
-scales detail on his robe