SLAYER of the INFERNAL
Slayers of the infernal are implacable hunters of demons, their mortal servants, and their earth spawn (commonly referred to as “half-fiends” or “cambions”). Within civilized society, a slayer of the infernal will seek out demonic sources of corruption. In non-civilized areas, or lands not under the jurisdiction of a ruler, the slayers of the infernal will hunt down and destroy their enemy. In most cases, slayers of the infernal will work with such characters as church inquisitors and hunters of the dead.
  The slayers of the infernal come in very diverse and manifold variety. Some are church-appointed agents of good and law, while others are motivated by personal reasons. All slayers of the infernal, however, share a number of extraordinarily useful talents and abilities, both supernatural and extraordinary, with which to confront the powers of Hell and destroy them. Most slayers of the infernal are paladins and fighters, although many other classes offer abilities and powers highly useful to a demon slayer.
  Hit Die: D10.

Requirements
  Alignment: Any nonevil.
  Base Attack Bonus: +7.
  Knowledge (the planes): 5 ranks.
  Special: The prospective slayer of the infernal must have successfully defeated a demon (of any type) or have driven a demon back to its home plane.

Class Skills
  The slayer of the infernal’s class skills (and they key ability for each skill) are Concentration (Con), Craft (Int), Gather Information (Cha), Intimidate (Cha), Knowledge (arcana) (Int), Knowledge (the planes) (Int), Knowledge (religion) (Int), Profession (Wis), and Sense Motive (Wis). 
  
  Skill Points at Each Level: 2 + Int modifier.

Class Features
  Weapon and Armor Proficiency: The slayer of the infernal gains proficiency in all simple and martial weapons, as well as light, medium, and heavy armors, as well as shields.
  Detect Demons (Su): The slayer of the infernal can detect the presence of demons out to 60 feet. At 5th level, the range becomes 120 feet, and at 10th level, the range increases to 180 feet. 
  Demon Bane (Su): The slayer of the infernal infuses his attacks with a magical bonus of +1 on his attack rolls and +1d6 on his damage rolls against all types of demons. This bonus is also applicable to half-demons.  At 4th level, demon bane increases to +2/+2d6, at 7th level it increases to +3/+3d6, and at 10th level it increases to +4/+4d6. 
  Furthermore, the slayer of the infernal gets to add his attack bonus to Intimidate, Listen, Sense Motive, and Spot checks whenever he uses these skills against demons or half-demons. Finally, he applies this bonus to Will saving throws against spells and attacks launched by demons and half demons, as well as opposed ability checks against demons and half demons. 
  Spells: Beginning at 2nd level (or 1st level if the slayer has a Wisdom bonus), a slayer gains the ability to cast a small number of divine spells. To cast a spell, the slayer must have a Wisdom of at least 10 + the spell’s level, so a slayer with a Wisdom of 10 or lower cannot cast these spells. Slayer of the infernal bonus spells are based on Wisdom, and saving throws against these spells have a Difficulty Class of 10 + spell level + Wisdom modifier.
  Penetrate the Infernal (Su): Whenever a slayer of the infernal casts a spell against a demon or half demon, the slayer gains a +2 bonus to caster level checks. If the slayer of the infernal has the Spell Penetration feat, this bonus stacks with the benefits of that feat. So, a slayer of the infernal who has the Spell Penetration feat gains an overall +4 bonus on his caster level checks against the infernal.
  Furthermore, a slayer of the infernal, having learned a number of weaknesses possessed by the infernal, gets to add +2 to the DC of his spells against demons. This bonus is cumulative with any other bonuses the slayer may have. For example, a slayer who has Spell Focus with Evocation, and casts an Evocation spell at a demon or half demon, his overall DC would be increased by +4.
  Immunity to Infernal Enchantment (Su): A 2nd level slayer of the infernal is immune to all Enchantment spells or effects created by demons as well as half-demons. Furthermore, he radiates a beneficent aura out to 10 feet. All allies within this area gain immunity to fear caused by demons, and gain a bonus to their saving throws against demonic Enchantment equal to the slayer’s class level.
  Damage Reduction (Ex): A 3rd level slayer of the infernal acquires resilience to the infernal. Whenever a slayer of the infernal suffers damage from a demon or a half demon, the damage is reduced. At 3rd level, subtract 1 point from the damage taken by the slayer of the infernal. Subtract 2 points at 5th level, 3 points at 7th level, and 4 points at 9th level. Apply the damage reduction to each separate attack.
  Additionally, the slayer of the infernal applies this damage reduction to any damage suffered from the natural environs of Hell, or any fiefdom created by a demon (regardless of its location). Apply the damage reduction to each attack separately, as with damage received from a demon or half-demon. In all cases, damage reduction applies to all attack forms, magical or nonmagical.
  Resist the Infernal (Su): A 3rd level slayer of the infernal gains a bonus of +1 to his AC and his saving throws against demons and half demons. This bonus increases to +2 at 5th level, +3 at 7th level, and +4 at 9th level. If the slayer wishes, he can forgo possession of any or all of these bonuses and bestow them on any ally who is within 10 feet per slayer level. He could break the bonuses up among allies, but the overall blessings cannot exceed his total.
  The slayer of the infernal also gains a spell resistance of 10 + his slayer class level + his Wisdom modifier. Thus, a 5th level slayer of the infernal with a Wisdom of 16 would have an overall spell resistance of 18. The spell resistance only applies to demons and half demons. It cannot bestowed upon any ally, as with the first component of this supernatural ability.
  
Slayer of the Infernal Spell List
  Slayers of the infernal choose their spells from the following list:
  1st level–bless weapon, cure light wounds, detect evil, divine favor, endure elements, magic weapon, protection from evil, remove fear, summon monster I.
  2nd level–aid, bull’s strength, endurance, resist elements, spiritual weapon, summon monster II, zone of truth.
  3rd level–dispel magic, greater magic weapon, invisibility purge, magic circle against evil, magic vestment, prayer, protection from elements, summon monster III.
  4th level–dimensional anchor, discern lies, dismissal, dispel evil, divine power, lesser planar ally, summon monster IV.

The Slayer of the Infernal
	Base	
Class	Attack	Fort	Ref	Will					Spells per Day
Level	Bonus	Save	Save	Save	Special			1st	2nd	3rd	4th	
1st	+1	+2	+0	+2	Detect demons ~ 60 ft., demon bane +1/+1d6, penetrate the infernal	0	-	-	-	
2nd	+2	+3	+0	+3	Immunity to infernal enchantment	1	-	-	-	
3rd	+3	+3	+1	+3	Damage reduction 1/-, resist the infernal	1	0	-	-	
4th	+4	+4	+1	+4	Demon bane +2/+2d6	1	1	-	-	
5th	+5	+4	+1	+4	Detect demons ~ 120 ft., damage reduction 2/-	1	1	0	-	
6th	+6	+5	+2	+5		1	1	1	-	
7th	+7	+5	+2	+5	Demon bane +3/+3d6, damage reduction 3/-	2	1	1	0	
8th	+8	+6	+2	+6		2	1	1	1	
9th	+9	+6	+3	+6	Damage reduction 4/-	2	2	1	1	
10th	+10	+7	+3	+7	Detect demons ~ 180 ft., demon bane +4/+4d6	2	2	2	1