@Natse
http://www.scp-wiki.net/beneath-two-trees
"Now the Serpent, who guarded the Tree of Knowledge and knew the secrets of deep magic, had looked to the East, and saw in those regions a brewing shadow. A new power was rising within an ancient kingdom, a power that swallowed all in its path. Old gods had been uncovered, and all their terrible rites now knew public practice. Most horrible of all, the Serpent saw the Scarlet King rising from the depths of the Abyss, rising to consume all of creation."
http://scp-wiki.wikidot.com/dust-and-blood
"Khahrahk was not great upon his formation: in truth he was small. He crawled around in the darkness of the abyss, but unlike his brothers and sisters, he knew himself and knew the abyss. So blessed and cursed by awareness, he felt pain and loneliness, and looked beyond the depths: but the thought of the light and the shade of the tree pained him more. Existence was pain, and he would have no part of it. It would be better to not exist. It would be better for all things not to exist."
"Upon this vow, he consumed his brothers and sisters, and grew strong on their essences. This act, this first sin of Khahrahk, caused him greater pain as he himself grew greater. He grew blind by his pain. So great was his spite and so absolute his hate, that he cursed the Creation and its Creator, and vowed to destroy the Tree and all that it supported in its branches and roots."
"With the borders of his realm set down, the King declared his war. His servants, and there were many, those birthed of the Darkness Below or those that had fallen to the King's service, surged out of his kingdom, and there was war with Creation. This war continues to this day, and shall not end until the end of all things."
http://www.scp-wiki.net/new-job
"If you're not familiar with the mythology of the Scarlet King I suggest you read up on him. There's plenty of unclassified information on him in the Foundation database. All that's relevant for now is that he is (to the best of our knowledge) the most powerful malevolent entity in the Multiverse."
Then there's the Hanged King, who rules over Alagadda, the dimensional nexus of the multiverse, and who is stated to rival Yaldabaoth in power.
http://scp-wiki.wikidot.com/scp-2264
"A terrible city, filled with equally terrible people. It is said that the Grand Karcist of Adytum serves the designs of an elder being, a horror thought to rival even the Hanged King of Alagadda. Craw! (SCP-2264-2 made a sound not unlike a crow) I should not speak of them. Not here."
So yeah...Swann sees these guys as a work of fiction. It'd be High 1-C if not straight up Low 1-B.