I am building a Ranger 4/ Slayer 7/Ardent 2 NPC. Now I wonder about the interaction of the Slayer's and the Ranger's Favored Enemy class feature:
The NPC is themed to hate Yuan-Ti, so he got humanoid (reptilian) as his ranger class favored enemy.
The Slayer class demands "a type of psionic creature" as the enemy he detests most.
I am not sure what "type" means in this context: A specific monster (like Yuan-Ti - I am using the psionic version in my campaign) or the types of favored enemies of the ranger with "psionic" added (like psionic reptilian humanoids). Either way I am uncertain whether the bonus of the two favored enemy class features would stack.
So these are my two questions: How specific does the Slayers favored enemy have to be and does the class features bonus stack with the same class feature of the ranger?