.HELP!!!

Here is what I remember (there might be part I mixed up with other mangas > maybe)

> where the mc woke up in his classroom in the middle of a lecture after spending time in a murim type world.

>Where when he was in the murim he had to fight to survive despite being weak. And because he was weak he died. whenever he dies it repeats itself till the guy learned and mastered martial arts and stood at the top.

> if I remember correctly he went to a portal with other people too. To fight monsters but it was in a isekai like world and no longer the modern. He choose not to be affiliated with a guild and went to a sort of tavern or mercenary guild (I think ) recruited some people... he was D or E rank than.

..I don't relly remember but if somehow you find it ... all blessings and love to you