Bad plot progression. Bro, if you set up an OP mc don't ever make him lose. Much less to an unnamed villain because it will make him look weak. It's alright for the MC to make mistakes but don't make him outright get destroyed. Also, his teammates are proving more of a luggage the more the story goes on. it's better if he becomes a one man army instead of carrying every neighbor/childhood friend he knows. It was already stupid when he tried to create an organization when he could've just trained silently without attracting attention, only interfering in secret.
So the mc's dumb as well. I thought that this was not one of those dumb mc's but well... What would he expect after letting the sorcerer with teleportation was left to escape. He should have killed her first and then random mooks. He could have killed them easily but she was a S class what did he expect.