So, I was almost certain that I'd read a discussion on here somewhere asking this question (or one similar) but I can't seem to find it now. And so, at risk of being redundant, I'll ask anyway.

On her special power, "Goddess of Anti-Life: Quintessence, range value of 6. At the beginning of your turn, you may deal 1 penetrating damage to all opposing characters within 6 squares," can an opposing character Outwit her special attack power prior to her gaining it? Such as, Outwitting her and then attacking and damaging her to the click?

It was ruled that her Quintessence would override the Outwit regardless, but I couldn't remember (or subsequently find) the answer I thought I'd seen somewhere on the Realms forum.

Technically, because of the nature of how it works, you could. But it wouldn't actually do anything other than waste an Outwit. Because if you knock her to that click, the Quintessence will override the Outwit and cause its effect to end.