I'm postng this one as a GM. I have a major villain who is a shadow lord human (ie a human born on the Shadow plane to human parents - see shadow lord template Bestiary 4). He is a summoner and I really think the shadow caller archtype (advanced race guide) is perfect.....but.....its specifically for Fetchlings. I'm always reluctant to "bend" the rules because it gives players at the table the perfect precedent to ask for their own preferred "bending" of the rules - leading to painful pleading and disappointment. Any thoughts - it does seem to me that an character with the shadow creature or shadow lord template which is a summoner would logically have access to the shadow caller archetype.
The 'Shadow Lord' template has 'shadow creature' as a prerequisite. Fetchlings and 'shadow creature' are basically the same with the difference that first is a race and second a template. Both are listed under Fetchlings in the ARG.
So your shadow lord is a shadow creature/fetchling and due to this fact he qualifies for the shadow caller archtype.
There is no rule bending :)
On the other hand .. NPCs and especially major villians should be something special. So an uncommon race, class or combination should not be impossible. As long as you are not showing the NPC sheet to the PCs they will never know what it was at 100%.
That's a great answer, thanks so much. You're right about the template, which is all the justification i'd need, but you're also right about no one knowing if i don't tell 'em :o). I'm going to have so much fun at the next session on Sunday......evil cackle!