After Ami won the gaming event which Taiki was co-hosting with Reiko, the two of them went into a back room to speak, but their conversation was interrupted by the sounds of Reiko's screams as she was attacked by Sailor Lead Crow. Ami transformed into Sailor Mercury to fight the Phage, but Taiki only left, thinking that he had no responsibility toward this planet.
Though Sailor Mercury valiantly tried to fight against Sailor Gamer, she had great difficulty. Sailor Jupiter arrived in time to help her out - accompanied by Minako and Rei in their cosplay outfits from the event, instead of their Sailor Senshi forms. Even all four of them together had a hard time standing against the Phage, but the Sailor Starlights finally arrived to help out after Seiya convinced them to do so.
The Inner Senshi, however, refused to let them kill the Phage, and instead did their best to stand against her until Eternal Sailor Moon could arrive to heal her with Silver Moon Crystal Power Kiss.
Because of Reiko's identity as a gaming idol, Sailor Gamer looked like a video game character, with green skin, white hair, fangs, and a pair of bat-like wings, and she wore a red and black outfit with pink accents.
Sailor Gamer was very strong physically, and used a variety of magical attacks which were powerful enough that the Sailor Senshi had a difficult time fighting her. Some of the attacks she used included the "Forest Wind Attack," the "Stormy Blizzard Attack," the "Vanish Bomb Kick," and the "Hissatsu Sonic Bomb."