Apologies for necroing the thread, but there are some things that still need to be considered.
I won't go into the pure psionic part, but I was looking through the rules for Spiritual Weapon and Empower Spell, and I'm under the impression that Spiritual Weapon (and many other spells) can indeed be modified by Empower Spell. This is all under the 3.5 system by the way.
One thing to consider is whether the effects and objects of the specific spell have ever, could ever, or will ever exist. If you had never cast, in this case, Spiritual Weapon, would the effect exist? No. Thus, even though one might say casting the spell creates an effect that is separate from the spell, it absolutely isn't. The effect is an inherent part of the spell.
This easily explains why most Summon spells don't benefit from Empower or Maximize: The creature or item already existed. The effect of the spell is only to bring the thing to the same location and in most cases bind it to the caster to do whatever. Since these properties have no variable, numerical value, the use of Empower and/or Maximize is wasted.
To quote Empower straight from the PHB:
EMPOWER SPELL [METAMAGIC]
You can cast spells to greater effect.
Benefit: All variable, numeric effects of an empowered spell are increased by one-half. An empowered spell deals half again as much damage as normal...and so forth, as appropriate. For example, an empowered magic missile deals 1-1/2 times its normal damage (roll 1d4+1 and multiply the result by 1-1/2 for each missile). Saving throws and opposed rolls (such as the one you make when you cast dispel magic) are not affected, nor are spells without random variables. An empowered spell uses up a spell slot two levels higher than the spell’s actual level.
Take note of how it uses Magic Missile as an example. Most people would say that the 1d4 is the only variable, but the description specifically adds that extra 1 in. D&D, in this example at least, appears to use the mathematics and computers definition of variable, which is:
10. Mathematics, Computers . a. a quantity or function that may assume any given value or set of values.
http://dictionary.reference.com/browse/variable
1d4+1 is a set of values and is, by the rules, variable. Likewise, claws doing 1d4 points of damage with a +1 strength benefit will do (1d4+1) x 1.5, because the damage done is still a variable.
Because the spell created those claws, the claws are the spell itself, meaning they can be Empowered. The variable part of the claws isn't just the 1d4 though: It's anything that can modify that damage, because it's a variable. If the claws get a +2 damage benefit from strength, the variable becomes 1d4+2. Since Empower explicitly states all numeric and variable effects are increased by one-half, the 1d4+2 is multiplied by 1.5 to determine the final outcome. If the attack happens to crit, that's still a variable effect is is also subject to the Empowerment.
So yea, the claws if you're going strictly by the book do indeed benefit from Empower and such. It's up to the DM whether this is too much.
