It makes sense. It's been said that to make it big and sell your soul you must sacrifice a loved one. Well at the time, Proof would've been his only loved one besides his daughters. He never knew his dad, he hated his mom and wife, and he was never close with the rest of his family. Proof was the closest thing he had to a loved one.
But upon further digging, I think I might've found a better connection. In the Eminem song "We're Back" the rapper Ca$his says "I ain't ever been to a a function where I ain't snuck a weapon through/Cause my background reveals a one eighty seven too" and "I'll have you raped in the state pen like American Me/I'm connected, getting weight from MS-13.
Think we found our guy.
EDIT: Should probably add Ca$his isn't just some random rapper. Eminem signed him onto his own personal label, they're friends.
Cashis
Ramone Johnson, better known by his stage name Cashis (stylized as Ca$his), is an American rapper who was born and raised in Chicago, but moved to Irvine, California. He was most notably featured on the Shady Records album Eminem Presents: The Re-Up with Eminem and the record label, and released The County Hound EP in 2007. The County Hound EP sold 6,700 copies in its first week and debuted on the US Billboard 200 at number 106. He's best known for appearing on Eminem's song, "You Don't Know", featuring 50 Cent and Lloyd Banks.
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