Set in season 1 everything that happened happened up until episode where riser Phoenix shows up everything happens just like in the manga and anime it's set in season 1, episode 8 Riser Phoenix So that everything goes how it is and rias is really not looking forward to it but To everyone's surprise (minus grayfia Because she already knew and issei Because he's still confused on what's going on) rather than riser showing up it's his sibling you. Rias is surprised by this change but is okay with it because she is rather fond of you.

Things basically played out the same as how it did in the episode like in Canon right up until the reveal for her fiance.

First into better one

Second intro is basically grok made Not the best In my opinion it's dookie