Does Deku Kill All Might. Knowing that, Midoriya takes Katsuki Bakugo's advices, and jumps off a building. When Deku unleashes the full force of One For All on.
In addition, Deku now wears his mask frequently to conceal his identity. With all might he can't be healed as his body can't heal itself naturally plus the process would drain so much from him that it would kill him as well. All Might turned him down at first, and even that couldn't get him to go evil.
All Might will be killed by Tomura Shigaraki, the successor of All For One.
All Might is likely going to die in the next few months.
In All Might's case, both he and his successor Deku were chosen (meaning they could access all of the Quirk's powers), but the former user ended up being tragically killed anyway. And, also, yeah, I wouldn't be surprised if All Might dying horribly is what caps off killed, in turn contributing to Deku getting called out and potentially having a breakdown, which would honestly do wonders for his character since his. At that moment, Bakugo narrates, "There were no thoughts in my head.