Although this article is based on canonical information, the actual name of this subject is pure conjecture.
"I approach the task of Kylo Ren really just as an extension of Darth Vader in a way. And I didn't want to get too close to it, but if you could convey in a few short notes as "The Imperial March" does—this evil power, strength, threat. It needs to be something that will hit you and [be] accessible right away."
The theme is introduced during Kylo Ren's first appearance in The Force Awakens, during the First Order's attack on Tuanul. The theme is played throughout the film, including the tracks "Main Title and The Attack on the Jakku Village" and "Kylo Ren Arrives at the Battle."
In introducing the theme for Kylo Ren, Williams approached it as an extension of Darth Vader and "The Imperial March," without being too similar. He wanted the theme to convey Ren's evil power, his strength, and the threat he poses in a way that would be immediately accessible to the audience.[3]
The Sound of a Galaxy: Inside the Star Wars: The Force Awakens Soundtrack on StarWars.com (backup link)