WAIT A DAM MINUTE

Nope hes not

huge spoiler
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yeahh yayul actually killed yeon bc he had a revenge towards yeon's other family ties (mom side) iirc, as in actually killed her, no misunderstandings no regrets, the abandoned empress way. i personally wouldnt want to give yeon a ml who killed her in the past.

they were strangers and didnt knew each other at all, even if yayul were manipulated to kill yeon, he still didnt hesitate to kill her so yes, yayul isnt the ml, ryu cheong is