Aflame Inferno

Aflame Inferno (불꽃의 인페르노) is a Korean manhwa series written by Dall-Young Lim and illustrated by Kwang-Hyun Kim, the former who is known for writing Unbalance Unbalance, Zero, and the Japanese manga Black God. The story revolves around Shi-Chan Kang, a high school student and fashion model who was nearly killed in a crossfire between demonic beings called "Tedlars". However, Inferno, one of the Tedlars, saves Shi-Chan's life by merging his body with his own. In order to separate themselves, they must collect 1,000 "Invento Hells" by killing other Tedlars in hopes of ever being separated from each other.

Plot
A self-absorbed high school student gets caught in the middle of a battle of demons (called "Tedlars"). He is nearly killed but is saved when the Tedlar named "Inferno" merged with him. Now he must hunt down Tedlars while keeping up with his studies.