The Mask of Ice, also known as The Masked Man, is the main Antagonist of the Gold, Silver & Crystal chapter in the Pokémon Adventures manga, serving as the leader of Team Rocket after Giovanni disbands it but before the Rocket Executives take over.
In the end of G.S.C. chapter Mask of Ice turns out to be Pryce, the gym leader of Mahogany Town.
Years ago, in his youth, Pryce had lost his two Lapras in an avalanche, leaving their child an orphan. Pryce reveals that all along, his plan was to go back in time to reunite his Lapras, La Glace, with its long-lost parents.
The Masked Man initially used Ho-Oh to kidnap Green, Silver, Carl, Sham, Will, and Karen as children based on their potential as trainers. Silver and Green escaped from him, and went to great lengths to figure out his identity. When Team Rocket disbanded in Kanto, he collected the remaining grunts and revived the organization in Johto with himself as the new leader and the remaining kidnapped children as administrators. The Masked Man's goal was to capture Celebi and make use of its time travel powers.
Gold was able to retrieve a scrap of his clothing and gave it to Professor Elm, who examined it and later realized that there were particles of the substance used to make Gym Badges owned especially by Gym Leaders on his clothes, revealing to Gold that he must be a trainer of some Gym.
The Masked Man first appears in the Ilex Forest, controlling the Charcoal Kiln and his Farfetch'd to battle Gold. He then appeared to Gold, who thought that his Pokémon were wild, and told him to leave this forest. He easily defeated Gold and disappeared. Later, he would show up to battle Silver and Gold at the Lake of Rage and reveals Silver's past to Gold before defeating them both by freezing the entire lake and sending them both plummeting toward the rock bottom, a measure that would have been fatal had Entei not arrived and saved them.
He then lays low at the headquarters and commands grunts to capture Suicune. To keep Crystal and Eusine distracted, he sent a Ditto disguised as Suicune to battle them. The grunts failed in their mission however and Suicune escaped because of Parsee's Spore.
He is then confronted by Lt. Surge at Team Rocket's new base in Mahogany Town. He defeated Lt. Surge, but he was able to escape and have his Electrode blow the base up. However, the Masked Man was confident Lt. Surge would not report him to the police since he was formerly a member of Team Rocket and would be arrested as well.
The Masked Man eventually gains the control of the legendary Pokémon, Ho-Oh and Lugia, both of which he captured before, and leads them to rampage at the Pokémon League so he can gain the secret behind the time-traveling Poké Ball from Kurt.
Later on, by completing the GS Ball, he captures Celebi in the Ilex Forest and goes back in time. Gold follows him and reveals his real identity, and eventually succeeds in defeating him and freeing Celebi. He vanished in the time vortex. To this day, no one knows what became of him.
In the HeartGold & SoulSilver chapter, Pryce finally returns along with Lance and Giovanni to stop the three legendary Pokémon created by Arceus. There, Pryce reveals that while he was trapped in the voids of time, he witnessed the beginning of the world, the births of legendary and mirage Pokémon, and a future that was destroyed by the three Pokémon created by Arceus. Knowing what lies ahead, Pryce called out to someone for help, and was heard by Lance.
Celebi, having sensed this beforehand, released Pryce out of the Ilex Forest Shrine, where they encountered Giovanni, who was waiting for Celebi's arrival to cure his disease. When Giovanni saw Pryce, he immediately attacked Pryce and would have killed him if it weren't for the intervention of Lance, who told them of the events going on at the Sinjoh Ruins. Although reluctant, the three Trainers formed an alliance to stop the destruction before it could begin.
While Giovanni faced Giratina and Lance faced Palkia, Pryce goes up against Dialga with his Swinub. Although Dialga had the ability to manipulate the flow of time, Pryce's past history with time gives him immunity to its attacks. After Arceus is calmed down by Gold, Dialga, Palkia, and Giratina leave to parts unknown, which finally ends the battle. After Celebi helps heal Giovanni's disease, Giovanni entrusts Pryce and Lance to train his son so that in the future, they may battle. In the meantime, Pryce decides to return to his Gym and resume his position as a Gym Leader.
Mask of Ice Pokemon
Pokémon: Detective Pikachu