Review: on 'ZZIRIT', Luísa Sonza brings Portuguese into X:IN's lab — the chemistry works in the video and production, but the spoken chorus never bonds

Two months after joining the remix of ENHYPEN's 'Bloody Paradise', Luísa Sonza is back in K-pop — this time as a guest on a title track. 'ZZIRIT' opens 'Chain Reaction', the first full-length album from X:IN, a quintet formed in 2023 (E.sha, Nizz, Nova, Hannah and Aria), released Tuesday (Oct. 6) with 11 tracks via VIVAI Entertainment; the physical edition arrives Oct. 20. The title is a Korean onomatopoeia for a tingle or sudden spark, and the whole record plays with chemistry: 'Brain Chemistry', 'Octane', 'Zero Kelvin', 'H2O', 'pH7'. Every member has lyric credits.

In this reviewer's view, the concept is its biggest asset. The 147-second video, directed by Alexey Figurov, cuts between a stylized lab and an outdoor stage, and Sonza slips into that world without feeling bolted on. The lyrics, moving between Korean, English and Portuguese, are a manifesto of self-confidence: doubters, envy and copycats, and a narrator who now 'flies higher.' It's territory the Brazilian has owned since 'Doce 22', and hearing Portuguese verses on a K-pop release still feels fresh.

The problem is the hook. The production is dynamic and the 'zzirit-zzirit' effect sticks, but the chorus leans on a half-spoken delivery that deflates the energy built in the verses — K-pop blog The Bias List called it 'the worst kind of non-chorus,' scoring the hooks a 5 and the production a 7. The criticism is fair: just when the spark should become an explosion, the song pulls back. For X:IN, seeking an audience beyond Korea, the pairing opens doors in Brazil; for Sonza, it's another stamp in her pop passport. What's missing is the chain reaction the title promises. Score: 6/10