First of all its mostly Yi Sang battle and your identity its clearly not best choice better choice Yi Sang with blunt dmg. Basically you need identity lot of blunt dmg at first phase you should gain as much sp for you sinners as possible and then second phase gonna start you should priorty trying to stagger dongbaek. When she gonna catch your sinners you should have full Yi Sang left SP 45 you understand and when clash in duel. Well this is how i win this fight if you need you can send friend request you could take as support one of my blunt sinners. Wish you luck comrade.

offset her evade, do not lose a clash (so go for dominating/ favoured only)

on her stagger, she'll kidnap everybody except for #1 deployed

so, use someone with a multi target ego (ishy blind obses/faust fluid sac)

also ut4 your ids