Yuri Kazinsky Seto (Kana: ユーリ・カジンスキー・セト, Kanji: 瀬戸悠里) is the name of the man who was responsible for the 2003 Deadly Flash incident. For his crime, he was sentenced to death, but his sentence was appealed in 2010. Subsequently he went hiding in the United States and in 2023 he resurfaced in The World R:X where he confronted Flugel. It is possible he is named after real-world terrorist Ted Kaczynski, the infamous UNAbomber, who like Yuri, mass distributed materials to cause random injury and death.