User blog comment:B214/Shin DxD 1 discussion/@comment-30230931-20180804194539/@comment-33939194-20180806211458

Ravep maybe immortal but Issei beating Riser in DX1 has proven that immortality can be beaten by someone more powerful and there are multiple people on Rias team that's stronger than Ravel. Ravel can be exploited as a weakness if focus is on her. Issei is strong but the problem is Issei is he is prone to falling into traps by opponents who are cunning and given how smart Rias has and how well she knows Issei, it wouldn't be hard for her to lure him into traps.