Cadence Seed Development Materials A basic material used to break through weapons and upgrade skills for Gauntlets Resonators.

An unusual substance resembling the shape of a plant seed. If you listen carefully, you can feel a pulse-like rhythm. However, in fact, this substance is not alive, and its structure is pretty similar to that of the Tacet Core of a Howler.
Sources
Abyss of Sacrifice
Synthesis - Transposition
Forgery Challenge: Moonlit Groves
Souvenir Store
Weapon Shop