User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-34061653-20180506195121/@comment-27973844-20180506204406

I would speculate that Rias will let Strada AND Croam Crush fight against Issei because Rias should know that Issei togehter with Ddraig are too strong for only one of them. Issei will defitely fight against Crom and with the appeariance of Strada, Issei will let Ddraig out of the Boosted gear so that he can fight against him.

Issei will definetly be overpowered by Crom while Ddraig has the upper hand against Strada. Strada himself is gonna bet on the time Limit Ddraig has and tries to survive until Ddraig will disappear, so that he can fight against Issei together with Crom. Issei will get more and more damage until he will unlock a new form or get the complete Control over Ophis and maybe a Little of GR powers. At the same time Ddraig will disappear and the weakened Strada and Crom are start there fight against Issei. After the match Issei is totally exhausted but can still fight. For the other battles, i think there should be equal except the battle between Grayfia and Akeno in which Akeno tries her best to buy Rias some time to defeat the weakened Issei together with Gasper.

After Issei arrived at Rias base, Rias will eventually praise him and say something like you have won a battle but not the war. Rias will then start useing her new transformation to defeat Issei and there fight Begins. Rias will have the upper hand but i think she and Gasper will be to careless and get attacked by someone of Isseis Peerage maybe Belphegor. Rias than tries to defeat her first but will get interrupted by Issei. After short time, Belphegor will try a suicide attack against Rias after she realized that Issei has reached his Limit.

Rias will think she trys to attack her and start a Counter attack. Rias than defeat Roygun but before she disappears, she will let the Magic power which target should be Rias hit Gasper who was behind her. Both Belphegor and Gasper are defeated and the final fight between Issei and Rias will start. Issei will mobilize his last strengh which is left in his Body to defeat Rias and Rias herself will try to defeat Issei with the POD without useing her Extincting Star attack, knowing that it would kill Issei in his current state.

At the and of the battle Issei will stand as the winner after he defeated her. At the same time, i think Akeno should already be defeated by Grayfia but Grayfia is not interrupting there fight because she will that Issei do it himself. Maybe while there fought, Grayfia has telled Akeno her reasons for helping Issei as his Queen, so that we will know finaly her main reason.

That's how i think the battle will be :)