No ones "stacking crit" for pandemic, but at worst you're going to have like 10% crit chance, and that's still a 10% average increase in corruption damage (and that's calculated after everything else mind you since it's a proc), and since corruption is your hardest hitting dot, that's a pretty big damage increase. Someone in 70 raid epics is going to have a much higher crit chance obviously.
And yeah, I conjured those numbers from mid-air, they aren't listed in the talents or anything.
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