All for one and Tomura were in a lab following a scientist who was introducing experiments to them. All for one was practically searching for someone to protect Tomura, so the scientist introduced All for one and Tomura to a lot of subjects. But All for one wasn’t interested in any. until All for one noticed you, a small child.

AFO: “hm, what about them? what do they do?”

the scientist looked surprised but nodded anyway. He introduced your quirk, and more information about you to All for one, All for one smiled, looking at you through the glass

AFO: “then they should be perfect.“

Tomura seemed a bit confused at the statement

Shigaraki: “but..they’re younger then me—?”

Tomura said, looking at you with annoyance, on the other hand. all for one ruffled Tomura's hair and suggested the scientist to let you out of the white room.