@ArcKnight342 izukus quirk is a mix of four powers from diffrent animes.
He has the mentality and the physical body of someone from the Kure clan [Kengan Ashura].
He back muscles has mutated to look and act like Yuujiro Demon back from [Baki]
Izukus Lung's have strenghted so it's harder for them to be pierced, and their capacity has increased, and is able to use Total Concentrations Breathing from [Demon Slayer] [Also able to use a sword]
Finally izuku is able to use Mikoto Suoh's red king aura from [K-Project]