The Elder God Chthon is mentioned in “Multiverse of Madness,” but is yet to appear onscreen in the MCU. Author of the Darkhold, the god of chaos is revealed in the comics to be the source of Wanda’s chaos magic. The MCU has depicted the Scarlet Witch as some sort of Avatar for Chthon, as Moon Knight is the Avatar of Khonshu. (Another “Moon Knight” connection!)
Should Chthon be unleashed on the world, the Scarlet Witch could be the only person with the power to defeat him. This would be an empowering moment for Wanda: Chthon’s influence in the Darkhold is what corrupted her during “Multiverse of Madness,” and liberating the world from his evil in an ultimate battle of chaos magic sounds like too great a spectacle for Marvel to miss out.
Chthon could also be a great villain to unite Wanda, Blade and the rest of the “Midnight Sons.” Witches, vampires and demons together in the MCU would bring together the franchise’s best and darkest horror elements, either on the big screen or during a Disney+ series.