I agree with Furio's assessment.
Defiance is a good idea, but it's implementation and visual support are a bit lacking.
#1: If Defiance had a countdown timer to give the Blaster the buff even after they are healed from the "danger zone", it would make the power a viable resource to be used after "paying the price" of almost faceplanting. BUT, in order to not abuse this "Click-type" buff, the HP range in which it kicks in needs to be dropped to approximately 30%. The buffs will be greater, but the buffs will last for [insert time].
#2: Also, in addition to the timer for the buff (which I think should be around half the time of Aim or Build Up), there should be a timer for the cooldown.(approxiamtely 2X or 2.5X the time of whatever time is picked for the buff from Defiance) so that yo-yoing doesn't become a normal part of gameplay.
#3: The Visual interface needs some help. If the previous changes were to be made, then the buff will be a bit higher when it does kick in, so seeing it on the Defiance Bar will be a bit easier, but the colors definately need to be changed to a red or a yellow.
#4: Also, as an added bonus, the timer effect coupled with a new interface would tell the blaster where they stand within Defiance so they can decide if the bonus they did get is enough to keep them in the fight without a viable source of healing.
The alterations that I'm suggesting are based completely off of how many Hit Points you have when you enter the target zone. I.E. if you get hit by a minion and go in, then the buff you receive will likely not be as high as it would be if a boss hit you and you almost die.
Let me know what you players think, becasue if we don't show some solidarity to these changes then we wont send a clear message.
Thanks.