PRiMA MATERiA

xi is a composer widely known for his orchestral, high-intensity sound, and PRiMA MATERiA marked his original-work debut in the series. Like ANiMA, his track for DEEMO, the title stylizes the 'i' in lowercase, and many players note a kinship in tone between the two. The song was first added as a premium exclusive and later, in the 2.10.0 update, received a Short Cut version playable in Normal mode.

In Normal mode the song is charted Single at S14, S18, S21 and S24, and Double at D17, D24 and D26. The D26 is the centerpiece: a pure stamina chart with runs that are very long for its BPM and almost no rest, forcing players to ride every less-dense stretch to keep the gauge alive. Compared with the D24 it greatly increases brackets, a 24th-note six-note half pattern that demands bracketing, and large back-and-forth staircases, sharply raising the physical toll; it is regarded as a high-end D26. As a bit of trivia, it has the second-lowest BPM among current charts rated D26 or above (187). The Short Cut adds Single S18, S21, S23 and Double D22, D24.

An on-screen line near the 37-second mark originally misspelled 'finally' as 'finaly'; the typo was fixed when the official chart video went up. The Korean title was rendered in an unusually quirky way that mixes syllables with the Latin letter 'i', which sparked a running joke in the comments on the song's videos. Notably, one user posted a piano arrangement of the track less than a day after the music and BGA were revealed.