User blog comment:Piyush Banerjee/Shin DxD 2 discussion/@comment-2607:FB90:4A8E:C500:80A:87B2:1048:97F3-20190609012154/@comment-36523287-20190610031014

Issei is a kind of late bloomers who develops skills later than his peers. He started off with a below-average strength. but now he is arguably the most powerful figther in his generation. Also regarding his performance as a leader, it should be noted that Issei was off to a bad start. He had never been trained and educated in leadership and needed to learn everything on the job. So, it's acceptable that his performance would be not as good as other kings. Finally, Issei being a Satan is a faraway future stuff. It's obviously not going to happen anytime soon.