I thought of an idea for some lore for Amumu. His lore is pretty basic and doesn't explain much of who he was and where he came from. My idea can be used with a release of another champion that could give him clarity when he/she comes to the League. There are rumors of a dry kit champion that is being worked on. I have just some random thoughts of how that person plus maybe another can expand on his lore. Here is my idea:
Amumu finds out his place of origin and what happened to him before his death. Amumu is from the outskirts of Bandle City. He was returning home one day from work when he was attacked by a small group of people in robes. This group is a religious group that lives near Shurima Desert that believes that the pyramids were built by a higher intelligent race/entity. They would prefer rituals/worshiping practices hoping that they could gain favor from these individuals and receive gifts or powers to help their cause. The leader of the group decided to try a sacrifice to see if they will get their recognition. They take Amumu, sacrifice him, wrap him in bandages, and place him within one of the pyramids. After a few years, Amumu is brought back to life by (healer champion that could be an existing champ or a new one) and Amumu was left with no memory of his past life.
The sand based champion was one of the religious followers that helped plan and execute the capture of Amumu. Amumu would like to get even for the events that occured to him and that he was taken away from his family and life.
Let me know what you think of this idea.