A group of Shadow Pokemon once led by an unknown affiliate of Cipher. After a fight which killed Blossom, a lethal cycle of revenge between its members and Jace began, not ending until long after the timeskip.
Most of the group found themselves in Treasure Town, and took up residence there until they were able to relocate to a Rediscovered Cipher Base. They were able to use the remaining technology there to create an ad hoc Shadow Pokémon machine, which they used on Shy Glaceon and Persian.
By the time Persian had been turned into a Shadow Pokémon, only two of the Shadow Pokémon remained; after an encounter with a witch, they decided to use some newfound knowledge to resurrect their fallen members, ideally using Jace's body for one of them. Their first attempt was nearly interrupted by H1's attack on the base, during which the three Pokémon were knocked out.
A Rhyperior, short on words and keen on strategizing. He tended to stick to working under whatever orders were given to him, until the Tyranitar seemed to vanish and Impostor was apparently killed by Jace; from that point on, his goals became more focused on getting revenge. Once Impostor revealed himself to the group after the timeskip, Zhang reverted to following through on the Ditto's plans, until one of them led to Sarabi's death; assuming her killer to be Jace, and mistaking Ditto's purification and disappearance for death, his desire for revenge was only strengthened. His want for revenge was only made worse by his discovery of Tyranitar's corpse, quashing the small victory of converting Persian; in his rage, Zhang attacked and killed a nearby Flareon, completely unaware of his relation to Jace. Abandoning the plans for resurrecting Sarabi using Jace, he returned to the base with Brendis' body.
After the fight with H1, the Earth Plate was embedded in his side, its power boost effectively nullified by the pain that it caused. When Jace stormed the base shortly afterward, Zhang was knocked out, and taken to be purified. Dealing with the guilt of what he'd done as a Shadow Pokémon, he ended up an easy target for Holzer in his search for the Plates.