Varus suggestion for the marksman update

Just a simple buff to ADC , the one that builds crit. I was reading a thread talking about how silly some abilities that crit are, referring to examples such as these . I got the idea that maybe certain abilities could have a crit function and scale off of crit damage boost from . I propose that gains a critical hit ability function on his Blight detonation: The detonation damage on enemies with 3 stacks of Blight will critically hit. We all know how much you love the stack 3 mechanic, so how could you say no? All that would have to be done is tune the normal detonation damage values down from 2/2.75/3.5/4.25/5% to: 1.5/2/2.5/3/3.5%. This would give actual meaning behind his % health magic damage that only really exists once maxed in rank. At max rank, it would deal 21% of a targets health as magic damage, and when boosted in crit damage from it would deal 26.25% of a targets health as magic damage. I think this would be fair, considering how mediocre it will be early on.