From The Heretic Knowledge Vault
One of the elves who intercept Sarine, Jon and Sara on the way into Praenubilus Astu. We don't know which one he/she is, but the officious Rhee, leader of the elven patrol, orders him/her and Ireum to "restrain these two" (Jon and Sara) while he proceeds to grill Sarine. Of course, things don't work out exactly as planned. Stay tuned; his/her time in the sun may be still to come.
A character by this name appears in an episode of the Chronicles of Heretic Knowledge, the omake that serves as Saturday filler while the strip is on a twice-weekly schedule. It's unlikely that the two Yuans are the same, although Impy has indicated that the omake Yuan has appeared in the story. What she wrote there was treated as a "spoiler," so it's not reproduced here.