King_Admiral_
Hm... Actually, he doesn't need the Attack Titan if you decided to add Breath Styles from Demon Slayer. Well, I prefer Thunder Breathing and Water Breathing. The former focuses on speed which technically can easily catch up to Levi when it comes to fast attacks and killing in one blow since the Breath Style itself is mainly for beheading enemies. The latter was for the fluid movements plus it has that Splashing Water Flow that you can use while using ODM Gear to jump from trees to trees without suffering any injury on your feet because of speed when flying.