Eclipse
Ability effectively the same as it is now - press button - duration based/recastable.
Damage Reduction
The more active Mirage is (aka moving), the more damage reduction she gains.
The more athletic movement (jumping/rolling etc) the faster DR is gained up the same max based on strength mods as now.
After a grace period of not moving, DR starts to decrease (slowly).
Damage bonus
Mirage gains strength the more she hits (not kills) enemies, upto the same max as now based on strength mods.
After a grace period of not hitting enemies the damage bonus decreases (slowly).