Resonators Monsters Weapons Items
FF Tidal Residuum Development Materials A material used for Weapon & Resonator Ascension and Skill Upgrade.

A unique formation resembling a tide-breaking vessel, found only on a few powerful Tacet Discords in Rinascita. Legend say Tacet Discords bearing this Residuum can chart the course to the Journeying Paradise.
Sources
Synthesis - Purification
Synthesis - Transposition
Drop: Tacet Discords influenced by the Dark Tide