how do i get a annihilus charm

Aparently there is something that i have to do or find to get this charm and why can't i trade 4 it. plz help me with this guys ladder is so confusing to play. PS i have some titans and a barb war cries gc for the answere a when i get it i'll be happy to give these to you.

The answer you seek is right here, although not all the information on how to spawn Uber Diablo is correct. I have a stuck thread in this section telling you how to do so.

wait for uber diablo to spawn in your game, kill him and he'll drop annihilus