Dragon Compendium Ability Enhancer uses

[Matamane]

The feat says

Any transmutation spell you cast that enhances ability scores increases the ability scores by +2 more than it normally does

Does this only apply to enhancement or any modifications to ability scores, such as enlarge person or giant size?

Likewise would a penalty be increased by 2 as well?

[Quietus]

Considering "enhances" isn't a defined term, I think we fall to the rules of English here; That is, enhance = increase/make better = any time you boost a target's stats, including via Enlarge Person, that boost gets better.

As to when you reduce said stats... enhance and reduce are two different things. Even if they weren't, you're still going to take the reduction and add +2 to it; If you used anti-bulls-strength for instance, enhancing the reduction wouldn't give -6 strength, it'd give -2. Regardless, I'd say that no, it doesn't affect reductions.

[arguskos]

Agreed with Quietus. Ability Enhancer makes any Transmutation spell that gives you a bonus to your ability scores give you an extra +2. Note that animalistic power is a crazy spell with Ability Enhancer (one of my favorite Cleric feats; makes being the buffer way more fun).

And no, enhance=/=reduce in English, so Ability Enhancer doesn't touch reductions.

[PlzBreakMyCmpAn]

Does this only apply to enhancement or any modifications to ability scores, such as enlarge person or giant size?

Raw? Yes, but Raw is broken and contradictory.

RAI? The designers assumed you are stupidly overpowered PHB races (yes LA+0 races are the most powerful in the end) who are conveniently medium size. So they used the size table (but failed) and generate those... almost correct values.

[Zaq]

Devil's Advocate: I could easily see a reading implying that only spells that grant an enhancement bonus are applicable.

[Matamane]

True enough. but I am working with a persisted array of spells so I am cool with it.

[NekoJoker]

Well, I always thought that feat could have some cool Uses

I want to get a list of good spells to use that feat on, Besides Animalistic power and the typical enhancers like bull's strenght and cat's grace which other ones could be included?

and more importantly... which ones can be persisted?

[Matamane]

Incantarix Persisting in this order

Shapechange (Some Lawful Good Outsider/Titan/Pit Fiend/Balor)
Giant Size
Aspect of the Werebear
Greater Visage of the Deity (Good on Demon/Devil, Evil on Titan/Lawful Good Outsider)
Fox's Cunning
Owl's Wisdom
Eagle's Splendor

I can make a DC 63 Spellcraft Check by level 20