User blog comment:Piyush Banerjee/Shin DxD 2 discussion/@comment-41.13.20.174-20181224141815/@comment-82.145.223.6-20181227211117

I dont belive that Issei can defeat Diehauser in a straight 1v1 match .The reason is that Diehauser is older and has more experience, and say what you will but in my opinion experince matters more then pure power.

In a rating game the result will depend on the rules of the game. The rating games are made so that eveyone can have a chance of winning.

But in a battle between Issei's team againt Diehauser's team, i say the Diehauser will win, because he was not the Unbeaten Champion of the rating games for so long without a reason .

And also the 4 Devil lord(Maou) were forbidden form participating in the rating game because it will make the games unfair, Sirzechs's  peerage is said to be the strongest.