Milarepa

Jetsun Milarepa was a Tibetan siddha, who famously was a murderer as a young man then turned to Buddhism to become an accomplished buddha despite his past. He is generally considered as one of Tibet's most famous yogis and poets, serving as an example for the Buddhist life. He was a student of Marpa Lotsawa, and a major figure in the history of the Kagyu school of Tibetan Buddhism.