Should I Kill Cicero or Not?

He has 500 gold on him as well as his gear. Since you can pickpocket him and receive higher grade gear at the Dawnstar Sanctuary, it is really not lucrative to kill him. If you have completed the quest line for the Dark Brotherhood, and Cicerio is still alive at that point, he will indeed become a Follower.

Should you kill or leave Cicero?

To get his clothes, Cicero can be pickpocketed, giving him the poison. ... If the Ghost of Lucien Lachance is active while exploring the Dawnstar Sanctuary, Lucien will tell the player that it is not wise to kill Cicero, because the Keeper is a sacred position in the Dark Brotherhood.

Does killing Cicero make a difference?

Killing Cicero grants you access to his unique outfit and benefits, but loses on a pretty unique follower. He's the ideal stealth follower, and cares not for crimes. He can be quite amusing to those who liked the Annoying Fan from Oblivion.