Another person said it, but IzuToga is always an amazing choice for Villain Deku. As he can easily connect with villains due to his past. Especially if he hears Toga's story. Also, helping Toga with her blood addiction would be great for both of them. She's saved from blood craze, and he gets to help someone. Toga falls for him even more than before, and Deku falls for her true self.
If we wanna go full villain Izuku, toga is always a good option. He can help her with her blood addiction and would fall in love and admire her Quirk. He could even be the one to push her to evolve her quirk as shown in the manga and show during the MLA arc.
I am a fan of IzuToga but you could work in an angle where IzuJirou could take place instead to make a secondary villain within their ranks to confuse the heroes on who the other traitor is
I say IzuToga with TsuOcha and JiroMomo, the 2 other pairings for it is shown that Jirou is closer to Momo then the others same could be said with Tsuyu and Ochako (besides that I just like those 2 pairings)