Hello i've been searching manga about samurai who helping people in apocalyptic world, he become like a hero and hope for the weaks.

It's probably seinen, dark fantasy a bit gore and i'm sure it's not isekai theme.. the vibe like berserk or claymore..

I can't remember the rest, it's been a few years i read that

Maybe Drifters?

"The bastard has stolen something of grave importance... my panties!" (Genshiken Nidaime)