It is about a guy who is the sole protector of a dungeon/place. He teleported to a place with a pyramid and there were 3 dungeon hunters/slayers(??). Then his enemies created a game so that there will be many dungeon hunters/slayers.
His skills revolve around his scarf changing its color and the chance to get colors are random.
Am I making any sense? sorry but I am desperate to find that manga/manhwa(it is colored) 🙁

Yin Zhi Shoumuren

~4400 manga completed
~1700 ongoing...

OMG I can't thank you enough you are such a life saver