People have been theorizing about what would happen if Monoma Neito copied One For All since his quirk was introduced. The last battle this arc is between Izuku's team and Neito's team so we might finally get the answer. Here are the possibilities i can think of: 1- Neito's quirk allows him to duplicate and use someones quirk for 5 minutes but he can't use 2 quirks at once. OFA isn't a normal quirk and it's a fusion of 2 quirks so Neito might not be able to copy it. 2- Before passing down OFA, All Might explained that to receive the quirk Izuku had to train his body to be in top physical shape otherwise his limbs would explode. Neito doesn't seem strong physically so his body might not be able to handle the power of OFA and he could hurt himself badly if he tries copying it. 3- All Might could have been exaggerating when he said Izuku's limbs would pop off. Izuku was ripped after training for 10 months but nowhere near physical perfection. Neito might be able to copy the quirk and use the same way Izuku could at the beginning, suffering minor injuries from not being able to control it perfectly. 4- Neito copies the quirk and can use it normally with no other problems.