|Real name||Dong Xin|
|Alias||The Winter Heart|
|Species||Demon, Sorcerer class|
|Occupation||Demon Sorcerer of Ice|
|Fate||Blinded and banished by Shadow Strikers|
|Created by||Zephyros-Phoenix and Dingo-Sniper|
|“|| You will not be able to defeat me. Eternal winter shall soon blanket this world! There is nothing you can do.|
– Dong Xin
Like many of the Demon Sorcerers, in ancient times, Dong Xin ruled part of the Earth with until he was banished by a powerful Chi Wizard to the Demon Netherworld with a hammer.
After this, he established his own territory within the Demon Netherworld and covered it with ice. One day, a young demon named Linos accidentally wandered into Dong Xin's territory. Not taking kindly to interlopers, Dong Xin proceeded to hunt Linos, an experience which greatly traumatized the young demon. Dong Xin was stopped, however, by the timely intervention of Linos' mother, Hsian Ji, the Sound Demon Sorceress.
At some point, Dong Xin fathered a human-demon child named Aneira Evans.
At the end of arc 1, Dong Xin was one of five demons released from the Netherworld by Daolon Wong. Wong had intended for the demons to get revenge on the Shadow Strikers for his defeat, but the demons abandoned him to follow their own agendas. Some point after this, Dong Xin acquired a mystical artifact that mysteriously amplified his own abilities and powers, even allowing him to create living ice constructs.
It is uncertain whether Dong Xin was informed beforehand of the Shadow Strikers by Lang Yan. Regardless, Dong Xin seemed to show little interest in the group. Instead, following the defeat of the other members of the Demon Quartet, Dong Xin slowly made his way across the world creating various ice pillar in various major cities and landmarks. These ice pillars projected increasingly cold temperatures around them.
Utilizing one of his ice birds, he kidnaps Linos and takes him to his base deep in the Arctic in order to finish the hunting game they started long ago. Despite his best attempts, Linos was ultimately captured by Dong Xin. When Linos' friends arrived to rescue him, Dong Xin shot them down from the sky with ice projectiles.
They survived, however, and stormed his citadel. Dong Xin briefly gained the advantage and overpowered them, but was ultimately defeated and blinded by the Strikers, who stabbed both of his eyes, allowing them to gain the upper hand and banish him back to the Netherworld.