Cerberus

Cerberus (ケルベロス) is a god whose destiny is to guard the Manifest in Tales of Innocence. His reincarnations are Sian Tenebro and Sian's two biological canine brothers, Cer and Ber. Each of these reincarnations derives from one of Cerberus's three heads.

History
Hermana Larmo explains that Cerberus did not interfere with Naraka and that, because he was always alone, Vritra visited him. She comments that, although Vritra was lonely, Cerberus was even lonelier—forced to persistently guard the Manifest and never leave in order to keep intruders away. The only flashback involving Cerberus occurs after the events at Kelm Volcano in Galpos. Cerberus is shown with Asras, who has come to retrieve the Manifest, having completed Cerberus's trial of reuniting Devaloka. Although Cerberus had expected Asras, he claims he does not wish to forfeit the Manifest, which causes Asras to believe that Cerberus does not feel is worthy.

However, Cerberus simply claims that the Manifest feels good to bite and play with, but Asras states that such a thing is not his concern and takes the Manifest regardless. Before he leaves, Cerberus stops him and asks if he knows how to use the Manifest, which confuses Asras. Cerberus explains that the Primeval Giant's will is imbued within the Manifest and that two must stand before the Giant in faith and devotion, but only one soul may inherit the Giant's power. This initially leaves Asras speechless, but he then comments that he now has what he was promised before leaving. Afterward, Cerberus is left alone and whimpers that his mouth is lonely without the Manifest.

Subsequent dialogue elaborates on Cerberus's role in the overall plot. In one skit, Ange Serena makes a comment about Cerberus being the protector of hell, and Hermana asks if Ange knows why Cerberus is called that. Ange believes it is because the cave behind Cerberus leads to hell, but Hermana explains that the cave is the place where souls are reincarnated and that the real hell is not like how it is rumored to be at all. Hermana then draws a comparison to Cerberus's fate as guardian of the Manifest, claiming that, to him, that place truly is a hell. Regardless of how many times Cerberus is reborn, he cannot escape his destiny of being the Manifest's guardian, which leaves him lonely and bored. Sian later explains that Cerberus was formed from the breath of gods in order to guard the Manifest—a matter in which he was given no choice. Even as Cerberus's life fades away, he will continuously rebirth where the Manifest is time and time again in an endless cycle.

Appearance and Personality
Cerberus appears as a small, three-headed gray dog—each face providing a different expression. He wears a red and white collar with three, confetti-like strands that dangle from it and is always shown in front of his Japanese-themed doghouse. Each time Cerberus dies, he is reborn as the same being in the same place, and the flashback in which he is shown just happens to be around the time when he was a puppy. This results in him being depicted as lighthearted and playful, albeit also lonely.

Trivia

 * Cerberus is based on the mythical Cerberus, also a three-headed dog—albeit with other animalistic features—who guards the entrance to the Greek underworld to prevent the dead from escaping and the living from entering. This is reflected in Cerberus's role in guarding the Manifest.