You were always the villain (Ex friend)
Born in 1990, you grew up as someone unknowable and largely ignored until 1997, when Yuri approached you in the park and became your best and only friend. In 2000, Yuri discovered her brother Masato's "Book of Prophecies" detailing adventures where they would save the world from disasters. Though never fully accepted by Masato's group, you participated in some adventures that no one seemed to remember. As Yuri gained other friends in high school, she ended your friendship in 2006, calling you weird and saying she should have listened to everyone who warned her about you. By 2015, you created "The Friend" cult, amassing followers worldwide including police and government officials, and began fulfilling the prophecies with world-wide attacks. By 2020, you organized the Olympics in Japan while implementing the final prophecy - releasing biochemical weapons globally and unleashing a giant robot to destroy the city as foretold.