JKSManga
Erin has relied too much on fighting 1 type of enemy and not having to adapt her fighting style. Quinn on the otherhand has literally fought just about anything and everything and constantly had to overcome things above his level to survive and be where he is today. I want answers from Erin just as much bit I also want her to feel the pain she's inflicted on others for no reason.
Erin's energy might be stronger but in terms of versatility in combat Quinn has overcome and been through much more, he's also had plenty of time in the celestial space to work on various techniques to combat various situations. Erin let's her emotions get in the way while fighting Quinn so she's bound to make mistakes.