User blog comment:Crimson and Darkness/Shin DxD 3 discussion/@comment-92.80.251.242-20191115082013/@comment-38340421-20191120205217

Because someone had to take over. It was felt she would be able to do it. Issei on the other hand has even less time then her. So he definitely wouldn't have been able to do it. Besides that school in general is a school for devils in general. Still being funding by the gremory family. Will be always a school in the shadows that supports supernatural stuff.