The first time Zoro used Asura against Kaku back in Chapter 417, Kaku twice referred to Zoro's Asura appearance as "Demon God" or Kishin (鬼神). Zoro has also prefaced each Asura usage with "Demon Aura" or Kiki (鬼気).
Kitetsu means demon piercer, and Enma is the Japanese version of Yama, the ruler of hell. When Arber asked Zoro if he intended to become a king, he chose to name his power-up King of Hell.
So, as far as demonic ties go, Zoro has more going for him.