Hikage Shinomori

Was a former Pro Hero and the fourth user of the One For All Quirk.

Hikage's Quirk called Danger Sense that allowed him to sense incoming threats in the surrounding area, giving him ample opportunity to react to them. According to Izuku, once a threat is detected, a stabbing sensation is sent to the user's head.

Hikage was a valiant and noble hero who was determined to defeat All For One. However, he was well aware of his limits and understood he couldn't defeat All For One by himself, so he spent his life training himself and strengthening One For All to be passed onto the next user. Hikage was described by Daigoro Banjo as a "weirdo" who preferred to spend his time in solitude. It is implied that this was due to his quirk constantly putting him on high alert.

At twenty-two, Hikage was entrusted with One For All by the third user at some point in the past. However, understanding the wide gap in power between himself and All For One, he chose to spend his time on the run and training to strengthen One For All in order for it to be stronger when he eventually passed it on to the next user. Eighteen years after inheriting One For All, however, his body started to break down, due to his body not being able to handle the stockpile of multiple Quirks. It was around this time that he passed One For All onto his successor, Daigoro, before dying of "old age".

(Source: Wiki)