Reverse: 1999

Version 3.7, titled On Another's Sorrow, launched on August 13, 2026, marking Reverse: 1999's 3rd Anniversary. The update concludes the 3.0 story arc and introduces two new 6-star characters: Rhiannon, a limited Beast-Afflatus bird trainer, available in her banner from August 13 to September 3; and Ms. Stranger, a Mineral-Afflatus spy whose banner runs September 3 to 17. The free 6-star character Coppélia, a Mineral-Afflatus construct tied to Manus Vindictae's rituals, is claimable by logging in during the anniversary period alongside 67 free summons, a selectable Artifice, and a Cut-to-fit Garment. The new 5-star character Silverwing Eagle (Plant) is earnable through event completion, and 4-star Lady by the Lake (Plant) is also added to the roster. Euphoria enhancements in this version cover Nautika and Regulus. New gameplay modes introduced include the resource-survival challenge Truth a Posteriori, new Focused Flashback stages, a continuation of The Syndrome of Silence, the return of Musae's Arcade with the 8-Bit Arcade Remix: Beach Battle mode, and a new Wilderness theme pack. Seven new character garments arrive alongside the update, including outfits for Coppélia, Nautika, Fatutu, Name Day, Charon, 37, and Spathodea.

Reverse: 1999 is a turn-based tactical RPG in which players assemble teams of up to three Arcanists, magical beings who coexist uneasily with ordinary humans, and lead them into card-driven battles. In each fight, players draw a hand of incantation cards belonging to their active Arcanists and either play them individually or combine two or three identical cards to upgrade them into more powerful versions. Higher-tier merged cards deal greater damage and trigger enhanced effects. The Resonance system adds a second layer of strategy: when all three Arcanists share the same Afflatus type (Beast, Plant, Mineral, Star, Intelligence, or Spirit), the team enters Resonance and gains significant stat bonuses, so team composition is a constant tactical consideration. The player fills the role of Vertin, the Timekeeper, an observer who remains unaffected by the Storm and can travel between reversed eras contained within an old suitcase that serves as a portable home base.

The setting is an alternate history 20th century in which the practice of Arcanum, a form of magic, has existed alongside ordinary human civilization. On December 31, 1999, a phenomenon called the Storm began reversing sections of the world back into earlier eras. Vertin's mission, assisted by the Foundation's operative Sonetto, is to locate Arcanists scattered across different decades, from the Roaring Twenties through the Cold War and on to the millennial turn, and save them from being erased from the timeline. Each story chapter introduces new eras, characters, and the political tensions between Arcanist-supremacist factions like Manus Vindictae and the broader human world.

Beyond the main story, the game offers a range of permanent and rotating modes. Permanent modes include the deep-dive exploration of Reveries in the Rain, the hardcore challenge Mane's Bulletin, the roguelike-adjacent Pre-Storm Protocol, the strategy mode Critter Crash, and the character-narrative mode Anecdote. Seasonal and rotating modes such as Musae's Arcade (multiplayer party gameplay), Focused Flashback, Tides of Thought, and Truth a Posteriori expand the endgame. The Wilderness system provides an optional base-building and decoration space. Progression involves leveling Arcanists, equipping Psychubes (personal equipment that provides passive stat bonuses and effects), and applying the Euphoria character-enhancement system to unlock upgraded skill variants for eligible characters. The gacha system uses Clear Drops and Unilog as the primary summon currencies, with standard and limited banners that follow a pity structure.