I always thought it’d be interesting if Corruptions skills had a baseline effect on cast with a short window to suffer a downside to enhance the effect, but with no initial self-conditions. That way Corruptions feel like a way to increase power at a price and reward intelligent use.
For instance, Consume Conditions could clear conditions and heal, then give you a few seconds to choose to take a few stacks of Vulnerability to decrease the cooldown by 3 seconds; Epidemic could transfer conditions on cast, then let you gain Weakness to do the present effect; Blood is Power could Bleed the enemy and give you Fury, and let you Bleed to give AoE Might and briefly make allies’ attacks unlockable.
Then Master of Corruptions could be reformatted to work like the Mesmer’s Mantra trait and let you Corrupt twice per cast, suffering the downsides each time.