Against Eu , spam stun and continue basic stun - throw - spin combo until a crit comes and go for the kill.
Against Chn- Hit them with physical Dmg and mag dmg reduce debuffs, along with the low level vitals. Hit them with a few hits to get their hp below full, then hit the physical and magical defense decrease debuffs. Go for a spear throw, 2 of the stuns, and you should be able to spin 2 win.