Does a bloodrager's claw attack damage increase stack with the bonus granted by the Rageshaper archetype's Bestial Aspect?
Draconic bloodline claws:
At 1st level, you grow claws. These claws are treated as natural weapons, allowing you to make two claw attacks as a full attack, using your full base attack bonus. These attacks deal 1d6 points of damage each (1d4 if you are Small) plus your Strength modifier. At 4th level, these claws are considered magic weapons for the purpose of overcoming damage reduction. At 8th level, the damage increases to 1d8 points (1d6 if you are Small). At 12th level, these claws deal an additional 1d6 points of damage of your energy type on a hit.
Rageshaper's Bestial Aspect:
At 4th level, whenever a rageshaper gains a natural attack through the use of a polymorph spell, he can increase the damage done by that attack by one die. If the spell grants multiple natural attacks, the rageshaper must choose one kind of natural attack for the ability to enhance. At 9th level, if the rageshaper's altered form grants him a new mode of movement, that movement's base speed increases by 10 feet. This is an enhancement bonus. If the rageshaper's bloodrage powers already grant natural attacks or alternate modes of movement, then the bonuses granted by bestial aspect also apply to these bloodrage powers.
My instinct is that they should not stack since they both seem like effective size increases, but it makes the Bestial Aspect ability seem a little redundant if it only affects my character from level 4-7.
To clarify, I'm under the assumption that both of these effects qualify as effective size increases, not actual size increases. Per the FAQ:
As per the rules on size changes, size changes do not stack, so if you have multiple size changing effects (for instance an effect that increases your size by one step and another that increases your size by two steps), only the largest applies. The same is true of effective size increases (which includes “deal damage as if they were one size category larger than they actually are,” “your damage die type increases by one step,” and similar language). They don’t stack with each other, just take the biggest one. However, you can have one of each and they do work together (for example, enlarge person increasing your actual size to Large and a bashing shield increasing your shield’s effective size by two steps, for a total of 2d6 damage).
Finally, if they do stack, what exactly is the final result?