Vestigial Alchemy is a trait in Destiny 2 that can appear on 1 weapon.
What Vestigial Alchemy does
This weapon gains energy when you pick up Vestiges and allows you to create ammo at the projectile impact point for you and your allies. Special ammo mode unlocks at 50% energy, while Heavy ammo mode unlocks at 100% energy. To transform Vestiges into Special ammo, [Alternate Weapon Action] to activate Special ammo mode. [Alternate Weapon Action] a second time to activate Heavy ammo mode.
