How Many Demons Are on Runeterra, and Are They All Alike?

Tahm Kench -makes deals, then ruins lives, feeds on Misery. Confirmed demon.

-lives for war, Tahm calls him "brother" (perhaps not literally) and says war is a manly appetite. May feed on warfare, and violence.

-so called "Demon Jester". No one knows what he is, but he is a serial killer and his name is an anagram for "chaos", which he might feed on.

The figure that has come to be known as the Demon Jester is an enigma. No one fully agrees from whence he came, and Shaco never offers any details on his own. A popular belief is that Shaco is not of Runeterra - that he is a thing summoned from a dark and twisted world. Still others believe that he is the demonic manifestation of humanity's dark urges and therefore cannot be reasoned with.

-in his joke he says he is a "demon" bird, but that's only a joke. We do have speculation from his background. He seems not to feel pain, or express much emotion. Is the bird a demon...or is Swain? He's a master tactician so there is something Tzeentch like about him.

His face was so implacable that it was popularly rumored to be a mask, disguising something utterly inhuman beneath. More controversy surrounded the bird that never left his shoulder, whose name he whispered only to it.

- Most definitely getting backgrounds rewritten. But I can see Nocturne feeding off fear since he is a living nightmare. Fiddlesticks is the "Harbinger of Doom" but it's unclear what the doom entails.

-not a demon in the traditional judeo-christian sense, but since League has occidental and oriental themes, she could be a kind of Yokai (Japanese) or Yaoguai (Chinese). She feeds off of human life, although she is a trickster and seems to apply she uses lustful desire to draw in targets. She began to feel regret for what she was doing, and joined the league....but with the league gone....maybe she's still out there feeding.

- He only looks like a Yordle, but there's no way that can be true. He doesnt act like a yordle at all.