Reo Mouri

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Manga version

Reo came to the hospital to kidnap Natsume Hyūga and would have gotten away with him if Mikan Sakura and Sumire Shōda didn't see him. At the warehouse he and his group have captured Mikan and Sumire who tried to rescue Natsume. Reo told the girls that they would be sold and that Natsume would become part of their organization. He took his earring off and noticed that Mikan was unaffected, unlike Natsume and Sumire. Reo figured out that she had the Nullification Alice and after looking at her face, he noted that Mikan looked like "That Woman". Interested, he asks his colleagues to check "That Woman's" movements in the past. He is angry and saddened when he converses with Narumi through Mikan's Panda Headphones as he finds out that Narumi became a teacher, even though both of them hated the academy. He and his comrades lose Mikan, Natsume and Sumire when they escape, but were able to escape capture.

Anime Version

After his first failed attempt to bring Natsume to "Z", Reo returns a second time to the academy as part of a traveling circus. He motives are still the same( trying to kidnap Natsume), but he uses his alice to control Ruka Nogi into attacking people with animals. In the end his plans are revealed by Koko and is stopped by Narumi and everyone else.

Alice

He has a voice pheromone alice. That gives him the ability to control minds.

Source: Gakuen Alice Wikipedia