Doopliss

Doopliss is one of the bosses in the game paper mario the thousand year door found in area 4 twilight town when fighting him he will transform into a shadow copy of mario with similar hammer and jump attacks.After defeating Doopliss he completely steals your body and you awake looking like the shadow copy[plus you don't even know his name after the battle]and he gives  you three chances to guess his name if all of them are wrong you get a game over and if one is right he starts acting crazy and hides in the creepy steeple.After finding him in the creepy steeple he fights you in another battle with all your other partners on his side.After defeating him again you get your body back and you finish chapter 4.