Popular Pupitar (flashback)
Will specializes in Psychic-type Pokémon, and is initially a part of the newly formed Team Rocket alongside Karen. However, once Team Rocket's plans are foiled, they are approached by Bruno and Koga, who invite them to join them in the new Elite Four.
Will has a peculiar personality, as he was inducted into the Masked Man's criminal organisation of his own free will alongside Karen. He is also shown to be inherently cruel to Green, victimizing her due to her ornithophobia.
Will is particularly exceptional in Pokémon battling, as he was able to easily control the Legendary Pokémon Lugia with relative ease. Both Will and Karen were considered to be geniuses, and that no-one could best them when it came to Pokémon battling.
Will is identical in appearance to his game counterpart. When he becomes a member of the Johto Elite Four, Will's appearance is rectified to match his revamped game outfit. He also wears one of the masks shared by all of the Masked Man's subordinates.
Will was initially recruited willingly alongside Karen into the Masked Man's service. When Green is picked up by Ho-Oh and taken to the Bell Tower, Will and the other associates of the Masked Man appear before her. Later, when Silver and Green attempt to escape from his base, Will and the other Mask of Ice associates intercept their movements in the air duct. He attacks with his Natu, as Green severs a cooling vent, to obscure their escape. Will pursues them through the mist, but finds himself faced with Green's expanding Jigglypuff. Will later becomes one of the Team Rocket executives of the Johto region under the Masked Man's plan.
Gold, Silver and Crystal Chapter
Will confronts Green at the Ilex Forest alongside Karen, where he begins to taunt her, asking whether she is still afraid of Ho-Oh. Karen knocks her to the ground, as Will informs Green that Silver was no match for them. As if on cue, Silver's unconscious body collapses to the ground, as Will watches Green run towards him. When Silver falls into unconsciousness once more, Will comments that he is bored, prompting Green to get angry at him. Will wonders whether she is still suffering from her phobia of birds, summoning Ho-oh on the scene. However, Green stands her ground, much to Will and Karen's surprise. Enraged, Will and Karen order Ho-oh to attack her, but she counters the attack by summoning Zapdos, Moltres and Articuno.
Will instantly takes to Lugia's back, as Karen does the same with Ho-oh, as both factions engage in battle with one another. However, as Will attempts to attack Green on Moltres' back, Silver appears behind him. Will is surprised by Silver's sudden appearance, as the giant birds fly above Ilex Forest's shrine. Later, when Red and Blue arrive on the scene, Silver manages to scale up to face against Will. Will then sends his Xatu hurtling at Silver, who manages to block with his Sneasel. He mocks Silver, stating that both he and Karen entered the Masked Man's service of their own free will. Enraged, Silver tackles Will off Lugia's back, as his Xatu stops his descent.
However, WIll is taken off guard by Silver's Ursaring, Feraligatr, Kingdra and Murkrow, who proceed to attack him simultaneously. This sends Will hurtling to the ground below, as he manages to stumble up afterwards. Will orders his Xatu to attack Silver, but is surprised when his Feraligatr subdues it, throwing it into a nearby wall. He calls out in protest at his unconscious Xatu, whimpering to himself. Later, the Masked Man berates Will for letting the Pokédex Holders get near to the Ilex Forest Shrine, as Red, Blue, Green and Silver arrive before him. After the battle, both he and Karen are approached by Koga and Bruno, who invite them to join their newly formed organisation.
HeartGold and SoulSilver Chapter