ToME: the Tales of Maj'Eyal

http://imgur.com/l2clQmi

...I don't know what happened.it is not considered an error so no crash logs, and whenever I try to kill the copy, I damage myself.
it also doesn't move out of the stairs, and so I cannot continue playing this character.

I had this bug in Dreadfell, in my case related to a glitch with Precognition. The copy was unkillable but inactive; thankfully mine was not on the stairs. Did you split the timeline also?

no, I did not put a single point in the precognition at that point of the game.I simply beat the first dwarf dungeon, and then came back in, so norgan won't hog my exp.when I was coming back, that copy appeared.