Halcyon

xi wrote "Halcyon" for THE BMS OF FIGHTERS 2010 (BOF2010), entering it under the team Lyrical Signal. The track dominated: it took first place in the individual total-score category and was the first ever to break 200,000 points, a staggering gap over the runner-up's roughly 150,000. With a single work, xi went from near-newcomer to a top-tier composer, and his team claimed the overall victory. Many regard it as the song that opened a kind of BMS renaissance, fittingly echoing its own genre tag.

The title refers to the halcyon, a bird from Greek myth (tied to the legend of Alcyone and Ceyx) said to calm the rough sea. xi turned that image into a soaring, emotional melody built on piano and strings over his trademark high BPM. The BGA, by yama_ko, was conceived as a video with a deliberately "BGA-like" aesthetic inspired by the Halcyon Days myth, featuring a standout storm sequence in its middle section.

A Long Version appeared on Groundbreaking 2010 and later on xi's album Parousia. The track spawned numerous remixes over the years, present on nearly every one of the composer's albums and in other rhythm games such as Cytus II and KALPA, cementing its status as a classic.

"Halcyon" joined Pump It Up in the PHOENIX version. It offers Single charts at levels S12, S18, S20 and S22, and Double charts at D12, D20 and D24, giving beginner-friendly options alongside high-end challenges for advanced players.