When Corruption is refreshed, the crit rating is not updated to the actual crit rating of your character or the actual crit debuffs on the mob. Instead, the crit rating you had when you applied the first Corruption keeps "rolling" as long as you keep refreshing it. The same is true for percentual damage increases, namely Tricks of the Trade and Death's Embrace. This has lead to a rather unintuitive way of maximizing corruption damage: Pre-Pot ([Potion of Wild Magic]), cast SB and Haunt, cast UA or CoA while Haunt is in the air, activate [Nevermelting Ice Crystal], then apply Corruption. If you have 4pT10, try to prolong this sequence by filler spells to get that proc as well. When the boss hits 35%, reapply Corruption while using NMIC and a pot again. Ideally, get Tricks of the Trade on both occasions and bribe your RL to announce heroism at 35%. The damage difference is significant: The Corruption damage will rise by roughly 30%, increasing the total damage by more than 10%.
This trick has been mentioned in a blue post, saying it is actually NOT an abuse, but clever use of game mechanics.
Even if you don't want to use it, it is good to know that applying Corruption before your first shadow bolt hits is actually a bad idea. This is the reason for the starting sequence: Make sure (someone's) Shadow Bolt already hit the target when you apply Corruption.
хоть иногда думай перед тем как писать..
