Riser marries Rias

For this scenario can follow for different people though you can add viewpoints of others or their situations but main person number one riser will he be content with his harem and his a newly acquired girls or will his Newfound success turn his sights not just on other Devils but on other factions note for the Riser route you can change rias' peerage so that either Kiba and issei are female or just completely take them out and replace them with different characters and if you do the going after other factions you need to make him proportionally stronger so he can actually get those women

Next person to follow is Rias herself will she allow herself to be consigned by her fate of being riser's wife or will she try to break free from her fate.

The next two people are connected but depending upon which person you follow and how you write it it can go very differently and they are Ravel and Issei. In this route due to Riser not liking issei and Ravel getting her own evil pieces he gave him to her and now here's where the difference routes become apparent with issei will he try to gain back his his former master and Friends and harem or will he try to gain new found power and become the true Red Dragon of domination( or whatever power you want to get them) and take everything that he desires now on to Ravel following her since now she is out of her brother's peerage will she be content to just make her peerage her own or will she try to surpass her brothers and show them that she was the most powerful one out of the siblings all along ( for those who want to know she is very intelligent and supposedly she's the smartest of her siblings) for her peerage members you can simply make it her own little harem( male or otherwise) we can do something different with it

For all of these you can mess with gender due to Magic being present in the world you can even make the female characters futas if you want you can also add characters if you want. Note some powers gained with powerful beings or just in general have downsides and consequences for them.