Back in time

You had altered the memory of Nana in Izuku’s mind, but you knew Izuku deserved more than that. He deserved the original... and the world was missing its symbol of peace. Maybe this one for all user could fill in the gap until Izuku took up his rightful position. And fortunately Mei had made it quite clear that there wouldn’t be any paradoxes from time travel, meaning that nothing was there to stop you.

As time spun backward in the machine, you pondered what to do. Ren had one quirk that would prove useful, ‘revival’. It would revive any disabled quirk that had been lost by reigniting the embers that remained. All for one used it in case something happened to his quirk, but you wondered if it could be used on a one for all user who had already passed it on. But for now you had one goal, bring this Shimura to your beloved Izuku's side and help in making his life the paradise he deserved.

Stepping out of the machine you knew you had arrived, it was some sort of complex in the middle of the ocean. You had heard of this place, how Tartarus existed to replace it before it was destroyed. Destroyed in a battle between the One for All users and All for One, you had a chance to change that, but in truth it would have little effect on your timeline. No instead you simply sought to claim your prize.

With All for One's power you floated into a hiding spot, waiting for All Might and Torino to leave the scene. No need for complications. After all there was only one target required.

Then she saw Torino and All Might shoot away, now was her time to act. Stepping out of her hiding place she could see the bruised and bloodied hero standing defiantly. The villain stood proudly, cackling with purple lightning at his fingertips.

“Thank you for the wonderful comedy.” All for One cackled, smiling evilly.

“Then I suppose you’ll love me.” You shouted stepping into the scene.

“A civilian? I thought we got you all to safety.” Nana Shimura gasped before smiling “don’t worry I’m here. I’ll keep you safe.”

A transparent lie, one that the villain gleefully laughed at, “I’m glad you’re here fool, I wouldn’t dream of slaying dead Shimura here before showing how weak and useless she truly is by failing to save you.”

“Go!” She warned you but you simply smiled.

“No I don’t think I need to.” You smiled, forming black electricity in your own hands. And sending it at the villain, he responded with his own.

“A familiar power it seems, you must be related to the fool I took this from.”

“Your battle is with me All for One.” Screamed Nana, charging at the villain. An almost certainly suicidal act, one you stopped with one foot, unleashing Shoto’s ice stopping her.

“Wait how did you?”

“Since when does the hero have to be saved by the innocent?” All for one mocked but you smiled savagely.

“I’m no innocent, but let’s end this farce. Die”

It wasn’t pleasant the villain opened his mouth to laugh only for his throat to refuse to breath. Hands clutched around his neck, only to begin crushing his own throat. Using her quirk analyse she realised that this version of all for one's quirk was more powerful, unable to resist you took it from the villain. Before he finally croaked.

You then turned your sights towards your true target, Shimura was still frozen in your ice, “holy shit. You. Him. Who are you?”

“Sleep.” You ordered melting the ice and holding her **** body. She was quite beautiful, every bit worthy of Izuku.

A/N: suggestions, feedback and ideas are more than welcome