Some 5 minute mishmash ideas below:
1. Charge up Mechanic
Tap to swap between light/dark
Hold to charge up the amount of damage reduction/increase.
Power strength affects max % of dmg reduc/inc, Efficiency affects energy/s consumed while charging up, requiring heavy casting time for heavy damage gain. Can use casting speed% to increase the charge up rate.
2. Creation Ability Mechanic
Hold to switch between light/dark
Creates fields of light/dark OR throws light/dark canisters that affects enemies instead of a straight buff, affects teammates (50% strength)
3. Ramp up Mechanic:
LIGHT - Increases damage taken by enemies per shot similar to duviri decree, affects enemies in an AOE (not affected by ability range but something else instead)
DARK - Decreases enemy accuracy per shot, affects enemies in an AOE (not affected by ability range but something else instead)