[@Goliah] [u]The rest of this is assuming you forgot to edit your quirk section[/u]: Once again Goliah its not a matter of his parents quirk its a matter of HIS quirk. A quirk should have two functions only if one is directly comparable to the other. Captain East for example his quirk is 'the man of tomorrow' he has no real special power but his body is super human in itself capable of fast speeds, strength, and endurance. Though he is no speedster, he's no hulk, and he's not immortal. Your character's quirk is split into two halves. Super human speed, and endurance. And the ability to instantly recognize an attack the second time seeing it, and onward assuming it requires movement. Those two are quirks that aren't mutually coming from the same place. Once's enhancing his brain power, and the other is enhancing his power, and stamina. One of those needs to be chosen. I'd say that super human strength, and endurance (while it already exists in this roleplay) would be the better of the two by virtue of reaction speed being a trainable thing and having less of an upper limit that one can't bench press a car. 

And while the backstory part isn't the best way to get into a black tree fighting group I'll let it slide as at least its something. If you want tips still relating to the quirk I'd have background in some sort of fighting spot such as boxing and let him be a melee combat controller sort of deal even though real life fights, especially with quirk users, aren't the same as traditional boxing it gives him a ground work for solid foot work, and reflex training.