Augment Healing + Mass Lesser Vigor

[eamon]

If you look at the various cases in which it is possible to add a modifier where no existing value exists the spell always states that the subject or object is treated as having zero. Refer to Barkskin or Magic Vestments.

That's not surprising - you're talking about enhancement bonuses, which typically enhance some preexisting value. It's therefore not surprising to see explicit text about such base values which are enhanced. On the other hand, that's not the case with Spells such as Jump, which will happily boost a jump modifier of +0 or a creature untrained in the jump skill. Nor is it the case with other healing spells, which don't explicitly discuss healing creatures at 0 hitpoints.

There's no particularly good precedent for "spells which cure", but I don't see a reason to special-case it. (More examples are in my previous post).

 

[Shin Okada]

I'd be inclined to say yes, and I agree that it should be ruled consistently with the vigor spells. But I now do understand why someone would rule the other way.

As a counter to my own argument though, I could point to the blistering spell feat:
"This metamagic feat can be applied only to a spell that has the fire descriptor. A blistering spell deals an extra 2 points of fire damage per level of the spell."

If I apply this feat to a Summon Fire Elemental Swarm spell, who takes this extra damage?

Fire Elemental Swarm, maybe? But they are immune to fire damages.