I mean the man still need to hone in his skills, its not like O I find this very powerful sword I'm now unbeatable by default, but instead of practicing and honing in his skills he get defeated cause his skills trash spite having a powerful weapon.

They only want him using sword energy in these sparring/training matches, so hes only using 1/3 of his actual strength. Not a single one of them would win if he used all of his skills.

He be getting gangbanged over and over again

Not really "gangbanged" per say, but he's definitely been getting pounded out in all of his sparring matches recently. That's to be expected though (for the time being at least), considering the people who've been helping him train have just that vast of an amount of additional experience over him.