Armageddon is a high-energy Touhou Project arrangement by LeaF, introduced to maimai でらっくす UNiVERSE PLUS at its launch on March 24, 2022. The track reimagines 霊知の太陽信仰 ～ Nuclear Fusion (Nuclear Fusion), the stage 6 boss theme of Satori Komeiji from 東方地霊殿 ～ Subterranean Animism (Touhou Chireiden). Clocking in at a relentless 210 BPM and running 2 minutes 25 seconds, it represents the intense side of the doujin rhythm-game arrangement scene. LeaF originally submitted Armageddon to the BMS event 東方音弾遊戯9 (Touhou Ongaku Yuugi 9), where it carried the genre tag "Kyrie", a Greek term (Κύριε, vocative for "Lord") that later became the name of the song's gold title unlock in maimai. The track also crossed over into Sega's other rhythm games: it appears in オンゲキ bright MEMORY (added May 2022) and CHUNITHM SUN (added October 2022), making it one of the multi-Sega-title Touhou arrangements shared across their arcade ecosystem. In maimai, the DX charts span Basic through Master. The MASTER chart (designed by 翠楼屋 / Suirouya) features a dense 993-note layout with heavy Break and Touch note usage, while the EXPERT chart (designed by はっぴー / Happy) presents a demanding 12.9 constant that pushes the upper edge of its difficulty tier. The jacket art and movie were produced by Optie and セシル◇タイト.