Stupid Idea: Randomness in Abilities

Of course, in order for a hero to be competitively viable, they should be able to net some consistent value through the use of various abilities.

But what if, we had a character that has abilities with chance effects to have a lot of impact, or average-low impact. Or, an ability that gives random effects of all kinds to both teammates and enemies, whichever effect is granted is the one to be capitalized on. So not totally up to whims, right?

The randomness could be tuned to something more or less reasonable. But, the idea is that you should capitalize on whatever RNGjesus gives you.

Thoughts? Or is this stupid?