I'm trying to figure out if there is any point in using feral combat training with a bite attack. The appealing part is that you get 1 1/2 STR and 2 handed power attack if it's your only natural attck. But I'm unsure whether you can get an extra bite ttack from your Ki-Pool and whether you can use your bite as your Style strike attack.
Also I'm not quite sure which size increases will stack.
So for starters the naga bloodline for Bloodragers gets you a D8 bite. The wording below makes me believe that it's always on.
Serpent Fangs (Su): At 1st level, you grow serpentine fangs. These fangs are treated as a natural weapon, granting you a bite attack as a primary natural weapon. This attack deals damage equal to 1d8 (1d6 if you are Small) + your Strength modifier. At 4th level, your fangs are considered magic weapons for the purpose of overcoming damage reduction. At 8th level, the damage increases to 1d10 (1d8 if you are Small) + your Strength modifier.
This can be combined with the atavism Totem Rage Power for a d10 bite.
Atavism Totem, Lesser (Su): The barbarian gains a bite
attack; if she already has a bite attack, it deals damage as if
the barbarian were one size larger.
So can you further improve this with Lead Bldes for and Enlarge person for 3d8 damage or are you limited to enlarge for 2d8?
Browser ate my post, so short version:
1. Bloodrager bloodlines text says that powers only last while raging unless explicitly stated otherwise.
2. Core FAQ says you can have one size increase and one effective size increase in effect at a time for a given weapon/attack/whatever. So you could get the size increase from enlarge person and the effective size increase from either lead blades or your totem power. If you keep at it until 8th level, you can increase your base die to d10 as well since it is neither a size increase nor an effective size increase.
If you really wanna have some fun, go druid/monk with Shaping Focus and go flurry of behemoth hippopotamus bites. } : D