Daniel Mitchell is the leader of the United Imperium of Races, the host of the artificial Klyntar Symbiote Nullifier, and one of the many victims of the dimensional distortions that abducted countless beings from their home universes.
While Daniel is one to want to do what is right, he sometimes appears quite nervous. He had a slight fear of death, but this fear began to diminish after he arrived in the previous universe he was in. He is particularly vocal about what he's feeling, especially when he's feeling irritation or anger.
With a strong, if somewhat skewed, sense of justice, Daniel seems to have exceptions and conditions for everything: he hates murder, but if the 'victim' was in fact a murderer themselves that killed their killer's loved ones, then he'd be more lenient to the murderer's killer. However, a few crimes, notably rape, have NO exceptions in his books and will always result in murderous anger from him.
He loves electronics and anything relating to them, and has been, more than once, called a computer geek, a name he's actually proudly agreed with.
It was not long after that, however, that during the expedition to the world eventually labeled Ylakanea, that Daniel and Corrin admitted their feelings, but discovered Corrin's own super-increased longevity, meaning she would long outlive him. However, Dr. Egon Stetmann, who'd been researching Manakete and Taguel DNA, came up with a potential solution. In the end, Daniel underwent a procedure designed to bind Manakete genes (derived from Nowi's DNA) to his DNA, essentially turning him into a Human-Manakete Hybrid, giving him increased longevity and, later on, the ability to transform into a Manakete-type Dragon.
Later on, when the group discovered an Aedis-class Arkship, and the various Ethereal-aligned races and creations in stasis, Dr. Egon Stetmann and a few Cloned Nod Researchers created a modified retrovirus using Daniel's DNA and the DNA from the Avatars and Ethereals, giving Daniel Ethereal-level (and style) Psionic Powers, allowing him to decimate enemy forces, either by telekinetically tearing them apart or telepathically ripping their minds apart.
Sometime later, an encounter with the Anti-Venom and Hybrid Symbiotes, and the two Klyntar playing hot-potato with Daniel's body (with the group's Psychics helping to repair the mental damage caused by this afterwards), then a radioactive attack launched at him during an Outer Rim Confederation attack, requiring a procedure to cleanse Daniel's body of the radiation, resulting in the remnants of the two symbiotes merging and expanding into a new Klyntar, which Daniel dubbed Nullifier. Nullifier also merged with Daniel's Dragon Form, allowing Daniel to have increased power should he into his Dragon Form while transformed into Nullifier.