Sanguine Pasternack is a vampiric Russian mammal of unknown type, although he is thought to be a sort of fox-wolf hybrid. Sanguine is a master of deception and is a powerful fighter when he needs to be. He harbours a strong dislike for Hachiman, although he does respect some aspects of him, such as his overall positive personality, while Sanguine is either very angry or very depressed. Sanguine strives for family, although he is infertile after an incident involving Hachi having froze him beneath the surface of a mountain. He is one of the Dragon Lord's servants, having been promised with the ability to reproduce if he was to get rid of Hachi, as well as remove the everlasting feeling of coldness that Sanguine always feels.

Sanguine was born as the prince of a Russian vampire cult, known as the Kul't Oskverneniye. His mother was a vampire priestess, while his father was a demonic entity known as Daedalus, who was summoned by the vampire cult in order to bring about a "dark messiah". Sanguine was concieved that night, and for the next nine months, the cult gathered bodies of injured soldiers and warriors for Sanguine to feast on. When he arrived, the cult worshipped him like a god, and believed him the spawn of a vampire god. Sanguine grew up learning how to fight, as he was sent to kill Russian soldiers so he could support himself, and also fight off vampires who challenged his royalty. Due to his demonic heritage, he found it easy to fight off challengers, though nonetheless he needed training. One night, during his training, Russian soldiers stormed the cult's headquarters, and proceeded to burn the place and kill every last vampire they could find, in hoping to stop the brutal murders and kidnappings that were occuring. Sanguine was furious and attempted to fight the soldiers, his skills displaying impressive power, but he could not save his kin from being slain by the soldiers. Eventually, he escaped and saved himself.

Sanguine managed to escape from the Russian soldiers and spent his time in hiding. As he grew older, he found himself needing to feed more often, and decided this was the change he needed in order to exact revenge against those who slaughtered his clan that night. He spent months killing soldiers and their families, and taking their possessions for himself. He felt good about doing this, as he felt they deserved to be slaughtered for what they did to K'ult Oskverneniye. However, he later realized that the guards would've been under the orders of the Church, and so he plots his revenge against priests as well. After successfully killing the worshippers of a small church and cornering it's head priest, Sanguine decides to carve the symbol of K'ult Oskverneniye into his chest while he still breathed, and would proceed to whisper into his ears that his God is not there to save him, and that only Hell awaits him for allowing his followers to die. He drank from the priest and then returned to the darkness. For the next four centuries, he rinsed and repeated this process, eventually having to take a few months hibernation every year. This was to stop himself from going completely insane. Eventually, he would reach the modern day where depression would affect him sorely, missing his clan and wanting to get to know his father, Daedalus. However, he would be approached by a demonic dragon, known as Araki, who would offer him absolute power of the mortal realm if he got rid of a certain individual; Hachiman Shin-Ha. Sanguine soon found and discovered Hachi for the first time. A lone warrior, a demonslayer who was part of a samurai clan that now lies in ruins. He figured they were not to different, but he set the past aside in order for power. He walked straight up to Hachi and sent him flying. Sanguine and Hachi would soon fight atop a mountain range, fiercely and mercilessly, while they exchanged stories of their feats and what their goals in life were. Hachi claimed his goal was to get revenge on the dragon that slew him clan, hoping to make the world a brighter place. Sanguine replied that his goal was to gain power and control all of Earth in order to exact revenge on mankind.

While the battle was mainly in Sanguine's favour, Hachi would access a percentage of the Rage Gene inside him, and also his machine strength. With this, Sanguine was surprised by Hachi's sudden power raise, and was severely injured when Hachi launched a strike to the gut, sending Sanguine back. Although it did not take long for Sanguine to recover, and he charged back at Hachi, only for Hachi to kick him straight into the side of the mountain, where Sanguine would remain frozen. After a year, Sanguine managed to break out from his icy prison, and he decided he would hunt down and kill Hachi, seeing him as the embodiment of everything he despises, and yet somehow, he would respect Hachi a little in his goals, and Hachi saw how alike he and him really were, although this would not stop them from being enemies.

Now that that's over, lets get to more personal info! Sanguine likes to spend his time drinking expensive alcohol and fine dining in the cover of night, while sleeping during the mornings, not because of a vulnerability to sunlight, but because he simply finds the daytime boring. His fetishes involve physical pain and the letting of blood. Sanguine is a selfish character, caring only for his own needs unless they are from his master or demons of higher authority. He takes pride in his heritage, often feeling incredibly insulted when somebody makes racist remarks against demons, vampires or his home country, Russia. He is also greedy and wrathful, not likely to let down against somebody who has insulted him. He is in effect the worst kind of being, being lusftul as he knows he can't have kids, greedy so that he can enjoy his eternity, violent when somebody refuses him, gluttonous for blood and flesh, eternally angry at those who mock or hurt him, and fraudulous, often handing over fake artefacts or objects to those who he finds undeserving. However, he is loyal to his heritage, and will stop at nothing to protect the pride of his heritage or his masters.

He suffers from a terrible case of pyrophobia, despite fire not actually being able to harm him. It is down to how his kin died that causes his fear of fire and flames, and he will not associate with fire at all because of this. He tends to think fire-users are teasing or mocking him when they use their fire powers, though he will admit that he overreacts.