Actually, based on the first post from catDreaming, his interpretation is not plausible as it overlooks a key phrase in the wording:
Defensive Deflection:
When an opponent would deal you damage, you may roll your single <Power> die to Defend against the Attack and also redirect that damage to a nearby target other than the source of the Attack.
It states specifically that you use the defend against the attack. As with any defend action, this would use up the Defend (so there would be no defense against later attacks), and some damage could still get through.
However, in the most recent verion of Chapter 3, this was updated:
Defensive Deflection
When an opponent would deal you damage, you may roll your single [power] die as a Defend and also redirect that damage to a nearby target, other than the source of the Attack.
I suspect the change of the wording was to allow the hero to deflect damage which was not done through an Attack action. However, this wording does not change the initial order of operations:
- An attack would deal damage (but has not yet done so) - trigger
- Roll a single die as a Defend (before the damage is applied)
- Apply the damage from the attack (which uses up the Defend as that damage is the next damage dealt to the hero)
In my opinion, the only part of the interpretation in question is what gets deflected. This is very open to interpretation, as has been noted. Is is the use of the phrase "that damage" which is problematic, as it could be interpretted to be the amount of the Defend roll. This could lead to a hero rolling a 10 for defense against 1 point of damage, causing the reflected damage to be 1000% higher than the original incoming damage. This certainly needs clarification.
From a story telling perspective, it seems to me the most plausible interpretation is the damage which is stopped by the Defend is what is reflected (as detailed in Shadowstripe's Captain America examples). In my games, I will likely be using the following wording:
Defensive Deflection:
When an opponent would deal you damage, you may roll your single [power] die as a Defend against that damage. Redirect damage equal to the amount reduced by the Defend to a nearby target other, than the source of the Attack.
This covers both partial deflection (Incoming damage = 10, Defend roll = 5, hero takes 5 damage and redirects 5 damage to another target) and full deflection without increasing the reflected damage (Incoming damage = 5, Defend roll = 10, hero takes no damage and redirects 5 damage (not 10) to another target).
This also takes care of a character's innate defenses (say armor) reducing the effectiveness of the Ability. If the character would take 3 points of damage and has armor (3 points of damage reduction when in the Red zone), then this ability can't be used (since the hero would not take damage, negating the trigger). From a story telling perspective, it is unlikely heroes would use a major (Red zone) defense again damage that can be shrugged off.
But if the incoming damage is 8, they would still take 5 damage, triggering the reaction. If they roll a 5 for the Defend, this would reduce the incoming damage to 3, which would then be applied to the armor, negating the left over damage, and allow the hero to reflect 5 to another target.