User blog comment:Piyush Banerjee/Shin DxD 2 discussion/@comment-2602:306:CD9A:C860:A9B0:D607:7141:9234-20190706015400/@comment-2602:306:CD9A:C860:A9B0:D607:7141:9234-20190706205322

Experience can be a big deal. Issei only won against Cao Cao because of Samuel he used in a doll. As a fighter, he was outclassed by Cao Cao. His fight with Dulio ended in a draw but what's interesting is Dulio fought Issei in close combat despite being mainly a long range fighter. Vidar is tricky as Issei had a hard time dealing with Vidar's acrobatic kick style. To answer your question about Vali not using magic against Crom and Strada. It wouldn't really work as they are both too experienced. We already saw how Strada nullified Rosswiess magic and Crom is simply too strong. Issei doesn't have Strada's experience or Crom's raw power.

Infinity Blaster and Satan's Compression Divider are the same tier of attacks. In the fight against Azi, Vali used Satan Compression Divider and later use Satan Lucifer Smasher to finish Azi off. Those are 2 big time attacks that he use consecutively. Meanwhile we've seen Issei gets exhausted if he uses Infinity Blaster which means he couldn't afford to miss. Vidar was the only exception because Issei had dragon slayers which was super effective on Vidar due to his dragon base armor.

What? Crom is stronger than Issei and yet he admitted that his eyes or senses couldn't track Vali. The only way he could counter him was because of his intuition. Something that Issei doesn't have. Issei doesn't have intense knowledge on Vali's fighting style like it was against Kiba.

Vali has too many advantages on Issei which is why it was clearly stated in volume 24 that DxD L is overall stronger than P DxD.