This site has spoilers for Mistborn and The Stormlight Archive. By reading this you may not sue Kelsier 2024 for Cosmere spoilers.
Kelsier was born as a half-skaa and half-noble in the Final Empire on the planet Scadrial. He desired justice for the skaa, who were considered the property of the evil Lord Ruler and had committed many atrocities against them by the nobles. Kelsier killed many nobles, providing justice where there was none, but was captured during a raid on the Lord Ruler's fortress, Kredik Shaw, and sent to the Pits of Hathsin. He became a Mistborn and escaped, becoming known as the "Survivor of Hathsin," but his wife died there. Kelsier decided to overthrow the Final Empire and recruited a crew, including a street urchin named Vin, who was also a Mistborn. They created a plan to set the noble houses against each other and build up the skaa rebellion's army to take control of Luthadel. After an initial failure, Kelsier destroyed the Pit of Hathsin, inspiring the crew to keep fighting. Several important members of the rebellion were captured and to be executed, but Kelsier launched a rescue, during which he killed one of the Inquisitors. The Lord Ruler arrived, and Kelsier was killed, but he became a martyr for the skaa, and his crew continued his plan. His protege, Vin, attacked the Lord Ruler's palace and killed him. Kelsier became a god in the eyes of the skaa, and the Cult of the Survivor was created to worship Kelsier. His death was not the end of his story, as he even survived that, and he continued to protect the people of his land.