If this card is used as reaction, do you move after you successfully avoided death or do you avoid the attack entirely if you can move away?
After. You only ignore attacks if the card explicitly states so.
So you have to survive the attack, before the effect can be used.
Luckily, this skill comes along with a +1 Defense item. Grabbing Searing Vengeance and the Earthquake (for another +2) could help as well.