User blog comment:B214/Question and Answers 6/@comment-99.235.66.221-20161130072057/@comment-201.239.133.207-20161214020047

he fought the grim reapers with his demonic powers, which we already know surpass issei's by kilometers, that does not mean his body is stronger or more durable, also it is important to notice that he normally never engages into hand to hand combat without wearing armor....in that sense issei's body could be stronger and more durable than vali's