Reducing Damage as an Interrupt

Question

A friend of mine's assassin just got Sunspray Heritage which includes an encounter power- when hit by a radiant or fire damage, the triggering damage is reduced to 0. When he's in Shade form he's vulnerable 5 to radiant.

My question is- is the vulnerability applied before or after the effect- does the character still take the 5 "vulnerable" damage even after the damage is reduced to 0?

To complicate matters, it also says he regains hit points equal to the fire or radiant damage he would have taken.

Answer 1

The character heals the amount of damage originally dealt. He takes no actual damage.

The order of events is:

1. The character is hit by a attack dealing radiant damage
2. Damage is announced
3. The character announces that he is using Sunspray Heritage (Immediate Interrupt triggered on an enemy would deal fire or radiant damage to you)
4. The damage is reduced to zero via Sunspray Heritage, the character heals the same amount

Vulnerabilty states that any time you take damage, you take extra damage as well. In this example, the damage is never dealt. We only make it to "would deal".

Answer 2

Sunspray Heritage (Dragon Magazine #386) says "Reduce the triggering damage to 0. You regain a number of hit points equal to the fire or radiant damage you would have taken before reducing the damage."

The Rules Compendium page 225 states that both a vulnerability and a resistance apply. While I don't see an example specifically here, I would say that they take 0 damage. My logic is that the damage would be +5 for Vulnerability (so if you take 12 damage, you then get the extra 5 for 17). I would then agree that the character gets the full damage sd healing after taking into account the Vulnerability (healing 17).

Answer 3

I would argue that he does not get to include the vulnerability in the amount that he heals.

• The power is an Immediate Interrupt(based on the questions title), meaning you "act before the trigger resolves" (p268 PHB).
• Vulnerability applies when the character is damaged. On pages 276-277 of PHB it says "vulnerable 5 fire... any time you fire damage, you take an additional 5 fire damage."

So he would interrupt the attack, say for 10 radiant damage, reduce the damage to 0 so it wouldn't trigger the vulnerability, and heal 10 hit points.