Machine Gun Kelly released this track as a response to Eminem’s disses from his surprise 2018 album, Kamikaze. On “Not Alike,” Em raps:

He wants to keep up his tough demeanor
So he does a feature, decides to team up with Nina
But next time you don’t gotta use Tech N9ne
If you wanna come at me with a sub, Machine Gun
And I’m talkin' to you, but you already know who the fuck you are, Kelly
I don’t use sublims and sure as fuck don’t sneak-diss
But keep commenting on my daughter Hailie[…]

Eminem also name-dropped Kelly on the first track of Kamikaze, “The Ringer,” rhyming MGK’s name with Iggy Azalea’s, another artist he has beef with. The name-drop is included in a line mocking the flow of Lil Pump’s hit song “Gucci Gang”:

So finger-bang, chicken wang, MGK, Iggy ‘zae
Lil Pump, Lil Xan imitate Lil Wayne
I should aim at everybody in the game, pick a name

The title “RAP DEVIL” is a play on “Rap God,” Em’s 2013 single that was a major success and considered by many to be a lyrical masterpiece.

Eminem released his response, “KILLSHOT,” on September 14, 2018, eleven days after this song’s release.