Demon Hunter (Combat)Source Inner Sea World Guide pg. 286 (Amazon), Pathfinder Campaign Setting pg. 98 (Amazon)
You are well-versed in demonic lore.
Prerequisites: Knowledge (planes) 6 ranks.
Benefit: You gain a +2 bonus on Knowledge (planes) checks to know the powers and abilities of demons. You gain a +2 morale bonus on all attack rolls and a +2 morale bonus on caster level checks to penetrate spell resistance made against creatures with the demon subtype you recognize as demons.Source Weapon Master's Handbook pg. 24 (Amazon)
When you successfully identify a demon using Knowledge (planes), you can spend up to 9 stamina points to increase the morale bonus on attack rolls and caster level checks from Demon Hunter by 1 per 3 stamina points spent.