DogLickerGods
Author I understand that you have a great fetish with Chinese fanfics and you have made all that clear with the 2 previous voice fanfics that you left to make this one but it is really necessary that you make the protagonists of the original works so disgusting with one or two is enough but at least DO NOT REPEAT THE SAME RECIPE IN 3 FANFICS I would love to support you but if you continue like this I am afraid I will retire and I hope that in the future you will control your impulse to put everything as Chinese fanfics
Author have you read Dxd light novel yet? Dxd anime isn't the source for on Issei characters or any characters in the series actually, Dxd anime suck so much that it destroy every characters and its season 3 consider as fanon by a lot of people and force me to read light novel instead because atleast in light novel Issei is characters is likeable.
Another protagonist could be tsukune aono, making it heard in his inner voice that he is only around moka because he is strong and protects him, in addition to wanting to have relations with version with his real vampire version. You could also add to date a live: and make the heroines "spirits" hear that the protagonist only fell in love with them, not for loving them, but only for wanting to seal them, Make them listen in their minds how I only used them and in reality I didn't love any of them, just playing with everyone's feelings