Far and away one of the most enigmatic of dragon breeds, the Sinomorph is shrouded in near-complete mystery. While the exact conditions that herald its arrival are not certain, it is said to only appear when called upon by all six Zyumorphs. Record of its existence may be limited to folklore and ancient legends, but recent sightings seem to suggest this storybook behemoth may truly walk the lands of Valkemare. If the stories of the past are to be trusted, its appearance serves as a beacon of light in the face of looming calamity.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

The embodiment of anti-establishment and rebellion, Felix doesn't care about rules and regulations. He is against politics and fights for freedom. Felix is very violent and hot-tempered; however, when the situation calls for it, he can be extremely calm and level-headed. He hates Noir's followers and would do anything to cripple their power over his island.

Unlike other dragons in Nines's Gang, Felix is a tolerant individual when it comes to personal opinions. He acts friendly towards hatchlings, no matter what path they choose to take.

Felix claims to think about humans the way humans think about animals bred for food: he wouldn't go out of his way to kill them for no reason, but he also doesn't particularly care one way or another if they die.

He is the Spirit of Thundercrest Island. Moonlightflower, the Night Glory Drake, is treated by him as his child. She loves him and is willing to die for him, as he is for her.