Refinements:

R1: Phantom Flash

Upon causing an Elemental Reaction, increases Elemental Mastery by 60 for 12s. Moonsign: Ascendant Gleam: Elemental Mastery from this effect is further increased by 60. This effect can be triggered even if the equipping character is off-field.

R2: Phantom Flash

Upon causing an Elemental Reaction, increases Elemental Mastery by 75 for 12s. Moonsign: Ascendant Gleam: Elemental Mastery from this effect is further increased by 75. This effect can be triggered even if the equipping character is off-field.

R3: Phantom Flash

Upon causing an Elemental Reaction, increases Elemental Mastery by 90 for 12s. Moonsign: Ascendant Gleam: Elemental Mastery from this effect is further increased by 90. This effect can be triggered even if the equipping character is off-field.

R4: Phantom Flash

Upon causing an Elemental Reaction, increases Elemental Mastery by 105 for 12s. Moonsign: Ascendant Gleam: Elemental Mastery from this effect is further increased by 105. This effect can be triggered even if the equipping character is off-field.

R5: Phantom Flash

Upon causing an Elemental Reaction, increases Elemental Mastery by 120 for 12s. Moonsign: Ascendant Gleam: Elemental Mastery from this effect is further increased by 120. This effect can be triggered even if the equipping character is off-field.

Your support is more valuable than a primogem.