Cyttorak is an immensely powerful other-dimensional God or conceptual being who is a threat to Universal and Multiversal scale. Even Mephisto dared to say Cyttorak is the closest candidate to be the true Satan or the most powerful of all demonic entities in the Marvel Universe (above Dormammu, Surtur, Marduk Kurios, Shuma Gorath, etc) because he is the most militant.
Cyttorak is saw very close to sit on that throne
Mephisto's sarcasm was shattered when Colossus/Juggernaut (Cyttorak's new avatar in that moment) almost killed the Serpent. No to mention, before that match, Cain could have easily cast out the Serpent's possession if he used the Cyttorak’s power which was inside him, but he chose not to. Simply, the Serpent just was a small entertainment to Cyttorak. Even the narrator stated, "Cain could have used the power of Cyttorak to cast out the possessor, but Cain's will chose not to."
Tom Brevoort, an editor and senior VP of Marvel publishing, someone asked how powerful is Cyttorak compared to Zom and Shuman Gorath, Brevoort replied Cyttorak is an abstract mystic being so “I would place him well above Zom, and likely above Shuma Gorath depending on circumstances”
It is not a coincidence what it was stated by Brevoort is subtly pointed out on the panels comic, above ;)