Corrupt Avengers fill this sort of moral grey zone when it comes to paladins, as they cannot be evil, but they have sworn vengeance upon a particular foe so are not wholly good like a paladin would be so it sort of forces them into a neutral alignment although I guess you could have a good corrupt avenger struggling with their oath and continuing to be a good person overall.

Role: DPS

Characteristics: DPS that has a sworn enemy and uses corrupting evil to fight it.

Source: Heroes of Horror

Game Rule Information

The Corrupt Avenger has the following game statistics.

Abilities: Constitution for concentration checks and spellcasting, Strength for fighting your sworn foe, Charisma for all of your devestating abilities.

Alignment: Any Non-evil

Hit Die: d12

Starting Gold: N/A

Class Skills

The Corrupt Avenger's class skills are Bluff (Cha), Climb (Str), Concentration (Con), Diplomacy (Cha), Intimidate (Cha), Jump (Dex), Knowledge (local)(Int), Listen (Wis), Ride (Dex), Search (Int), Sense Motive (Wis), Spot (Wis), and Wilderness Lore (Wis)

Skill Points at 1st Level: (2 + Int modifier) × 4

Skill Points at Each Additional Level: 2 + Int modifier

Class Features

All of the following are class features of the Corrupt Avenger.

Weapon and Armor Proficiency: A Corrupt Avenger is proficient with whatever they were already proficient with.

Spellcasting: You have the ability to cast a small number of arcane spells. To cast a corrupt avenger spell, you must have a corruption score equal to or greater than the spell's level. Bonus spells are based on a number equal to 10 + your corruption score, and saving throws against these spells have a DC of 10 +Caster Level. When you get 0 spells per day of a given level, you gain only any bonus spells you would be entitled to based on your corruption score. You prepare and cast spells just as a wizard does; your spell list appears below. You can also prepare and cast corrupt spells.

You record your corrupt avenger spells in a spellbook, just as a wizard does. At 1st level, your spellbook contains two 1st-level spells of your choice, selected from the corrupt avenger spell list on page 90. At each new corrupt avenger level, you gain two new spells of any spell level or levels that you can cast (based on your new corrupt avenger level) for your spellbook. At any time, you can also add spells found in other corrupt avengers' spellbooks to your own, and you can also add spells from another character's spellbook (such as a wizard's or a wu jen's book) to your own as long as those spells appear on your class spell list.

Armored Casting: Because the somatic components required for corrupt avenger spells are simple, you can cast corrupt avenger spells while wearing light armor without incurring the normal arcane spell failure chance. However, wearing medium or heavy armor, or using a shield, imposes the normal chance of spell failure if the spell in question has a somatic component (most do). Wearing even light armor still imposes the normal arcane spell failure chance for arcane spells derived from other classes.

Detect Sworn FoeSp: You have the spell-like ability to detect the presence of your sworn foe. This ability is similar to the detect evil spell (see page 218 of the Player's Handbook) in range, area, and duration. In the first round of concentration, you can ascertain the presence of a sworn foe within the area. In the second round, you can determine the number of foes in the area and the power of the strongest one (as per the detect evil spell). In the third round, you can determine the strength and location of each foe.

Sworn FoeEx: At 1st level, you must choose a specific kind of monster or an organization as your sworn foe. This cannot be a broad category such as aberrations but must be a single creature type, like bugbears. You gain a +2 bonus on Bluff, Listen, Sense Motive, Spot, and Survival checks relating to your sworn foe. This bonus increases to +4 at 4th level, to +6 at 7th level, and to +8 at 10th level. Unlike a ranger's attack against a favored enemy, you do not gain a bonus on damage rolls against your sworn foe. Instead, whenever you face your sworn foe in combat, you enter a ragelike fury. You gain a +2 bonus to your Strength and Constitution scores. This fury lasts for a number of rounds equal to your corruption score, or until none of your sworn foes remain within sight (or within 60 feet if they are invisible or otherwise hidden from your sight). At the conclusion of your fury, you must make a Fortitude save with a DC equal to 15 + 1 per round that you were in your frenzy. If you fail this save, your corruption score increases by 1.

Taint Suppression: While you are likely to accumulate high corruption and depravity scores over the course of your career, this taint is not immediately obvious to onlookers. Your depravity manifests in the normal range of mental symptoms, but you can replace any physical symptom of corruption with the internal corruption symptom. If you enter a tainted area, your corruption immediately manifests externally, and you regain the physical symptoms you exchanged for internal corruption. These physical symptoms disappear 1d4 days after you leave a tainted area. It is otherwise impossible to tell, based on your external appearance, that you carry corruption.

Tainted StrikeEx: Beginning at 2nd level, you can infuse a melee attack with the power of your taint, adding 1/2 your class level to the damage you deal with the attack. If you strike a creature immune to the effects of taint (such as an undead creature or a creature with the evil subtype), the tainted strike has no effect. You can use this ability once per day at 2nd level, twice per day at 6th level, and three times per day at 10th level.

Grim ResolveEx: Starting at 3rd level, you gain a bonus equal to your Charisma bonus (if any) on all saving throws. This benefit does not stack with other effects that allow you to add your Charisma bonus to saves (such as divine grace).

Frightful FuryEx: Beginning at 5th level, when you face your sworn foe and enter your fury, all opponents within 30 feet of you must succeed on a Will save (DC 10 + your corrupt avenger level + your Cha modifier) or become shaken, taking a —2 penalty on attack rolls, saving throws, skill checks, and ability checks.

Unnerving FuryEx: When you reach 9th level, your fury becomes even more fearsome. Opponents within 30 feet of you who fail a Will save (DC 10 + your corrupt avenger level + your Cha modifier) become unnerved, taking a —4 penalty on attack rolls, saving throws, skill checks, and ability checks.