Magog is a character in the Muse-Verse who appears near the end of Phase2. Magog is a super-powered vigilante who rejects Superman's belief that all human life should be preserved.
His methods are controversial, many prefer his "permanent solutions" to Superman, others are terrified of him and see Magog as proof that superheroes need to be controlled by the government.
Magog never has his own movie or TV series but pops up in the movies of a lot of other DC heroes.
For most of phase2 and phase3, Magog is smugly convinced that the Justice League is weak and that their "half-measures" cause more problems than they solve. Magog believes that the only intelligent solution is to always be more ruthless than you're enemy. It's not until the events of "Justice League: Kingdom Come" that Magog will finally see where his way leads.