""Bought Cage's tape, opened it, and dubbed over it"
Thats a diss, he means he bought the tape and copied something over it.

Cage murders eminem on 3 songs:

"Illest 4 letter word"
"bitch lady"
"and so kiddies"

I can't believe you guys didn't realize that line was a diss

i think that my boy em sounds nothin like cage and that em will rip him in a battle just because he's em and he can do that