User blog comment:Piyush Banerjee/Shin DxD 2 discussion/@comment-32252462-20190204134259/@comment-86.164.164.228-20190207040132

The main reason Issei is a good main character is because he's a flat arc character with Issei and other flat arc characters like Goku from dragonball they are the one's who challenge the world to force the world to accept their dream. Their story is how the world reacts to them not how they react to the world.

Take them out of the story and the events that cause other charaters to grow don't happen because the world stays the same. Flat arc characters add flexability to the story while Possitive and Negative arc characters add depth. None a better charater type then the others but a good long running story need a combination of all types.