User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-34061653-20180321191336/@comment-34061653-20180321203546

Indeed, Issei can summon Draig and can both fight? So Issei's team has 2 god class fighters who are top 10 level. (Issei and Draig)

2 Satan Class (Grayfia and Roygun) Furthermore, Roygun was rank 2 of the top 10 best rating game players so her knowledge and experience gives Issei's team an edge.

Xenovia (Excalibur's scabbard which grants her invulnerability) not to mention has access to (Crimson Destruction Dragonar to boost her abilities)

Asia (best healing ability do to her Balance Breaker)

Ravel (as a talented tactician)

And rest are strong in their own right.

Yep Issei's team has become broken beyond belief. Especially since they just beat one of the strongest teams in the tournament.