xLucqs
Idea #1 - [Essence of Blank] - whenever he's not 'busy' he can use one of his 'quirk slots' as this power to 'Evolve' his [New Order] to have more 'quirk slots' and be more versatile and less restricted since this gives him 'unlimited potential'. Idea #2 - [One For All] - he can use one of his 'quirk slots' to give himself a "OFA" copy where he can use the 'transfer' aspect of the quirk to transfer it to one of his hairs which he can pluck, then he can use another 'quirk slot' to have a 'Adapt & Evolve'(akame ga kill/Tyrant) quirk so he can use it fully when he Eats the OFA hair. Idea #3 - [Drain Touch] - he can use one of his 'quirk slots' to get a power that let's him 'Drain' and 'transfer' anything of the enemy (Lifespan/Talents/Health/Quirk Energy/Memories/Stats) to either himself or someone else. (P.S. he can use this to offset the side-effects of [One For All] that is its 'Lifespan Reduction' effect.)
Man i understand that you dont want mc to beat easily all might in his best form, but dont nerf him, this Quirk along with mc's creativity and ideas from other mangas and shows has the potential to overcome easily all for one and shigaraki or at minimum to be stronger than them even if it is just a little bit. I Wont ask you to turn mc into someone that can beat all for one in one move, but is unforgiveable to not be at least equal to all migh in his pinnacle once the canon has begun and be at least 25% or 30% stronger than shigaraki at his best individually