Quest bug master of a million faces

i completed part of the quest where you open the portals on master of a million faces with my friend who had all of the pieces. i did not have all the pieces but i still got the reward. now i cant enter the chamber of sins level 2 and i can no longer find any of the pieces, they are not dropping. i still have two pieces, i just cant get anymore for some reason so i can open it myself.

Are you talking about the correct quest, cause The Master of a Million Faces doesn't need any pieces?
For entering "chamber of sins level 2" you have to kill Maligaro in the quest Essence of the Artist.