Little is known of Lewis's personality outside of his work in the cannery. There is a lot of marijuana paraphernalia in his room as well as remnants of the drug itself, suggesting his substance abuse stemmed from that, as well as alcohol. He is also mentioned as having the liking to play video games with Edith, although he was very bad at them. He was proud of his Indian heritage and saw it as a way to distance himself from being "just a Finch".
Lewis after going on a rehab developed a mental disorder. He noticed how boring his life was, and decided to change that by creating new himself achieving great things. This made him apathetic and depressed.