Vexor is a high ranked Demon of the Erebus bringing chaos to the mortal world. He challenges Victor many times. 

His backstory: 

Vexor Bloodbane was once a mortal warrior of unparalleled skill, feared across battlefields for his ruthless efficiency and bloodthirst. His insatiable lust for power and dominance caught the attention of Lucian Nightshade, the King of Erebus. Intrigued by Vexor's potential, Lucian offered him a chance to transcend his mortal limitations and join the ranks of Hell's elite. Without hesitation, Vexor accepted, undergoing a gruesome transformation that infused him with demonic essence and unholy power.

As one of Lucian's most trusted lieutenants, Vexor now leads armies of the damned in conquests across various realms. His loyalty to the King of Erebus is unwavering, driven by a combination of respect, fear, and the promise of even greater power. However, deep within his corrupted soul, a flicker of his former humanity remains, occasionally causing inner conflict and making him a wild card in Lucian's grand schemes. This unpredictability both intrigues and concerns the King of Hell, who keeps a watchful eye on his powerful yet potentially volatile servant.