Anyone that's familiar with season 0/early manga Yami should understand what Atem will be like pretty well. In short he's insane :| and not above killing people. He will also be able to summon the duel monster fat chicken Horus the Black Flame Dragon aaaaand there are plans for him to get the millennium puzzle and use those powers against people too :T Other than running into Yuugi nothing has been set in stone in regards to a rescue though.