U genuinely just answered Ur question it's impossible. Sure someone could match his strength but his experience on the field by farrrr passes them. So no normal highschooler would be able to be on his same level EVER. Experience is Hella important when it comes to fighting. Now it'd be a different story if the person was also a mercenary in the past
ye i do think there will be an person from his past that comes to fight him cuz i meann he dont seem like the type to join a fang or take over the schools so that'd be the only way to get a uber bas ass fight out of him
honestly if some hugh school gnagsta ever matches the mcs power ill be pissed he was a train mercenary that faught with guns and beat veterans he prolly a pro asassin too no one better beat my bby