Originally I was going to call it a paladin 'kit,' but the Inferknight is not exactly a 'different' kind of paladin.... more like a fighter who worships fire and has abilities based on the paladin class... but NOT a paladin. At any rate I posted this a LONG time ago, and it seems it is time to 'fire' him up again.. what with the paladin craze going on and all.
Ability Requirements:
Str: 13+
Con: 9+
Dex: 13+
Int: 9+
Wis: 13+
Chr: 17+
The Inferknight's main power will lie in his strength, so STR is his prime stat, but he does need to be beautiful, like fire, hence the charisma requirement.

Allowed Races: Human, Dwarven (the two races that can be assumed to have potential love affairs with fire.... I thought about including Half-orcs, but the charisma requirement sorta cuts them out... not that ALL half orcs are butt ugly pukes...)

Demi-Human level limit: 12 (can be exceeded by high prime stat rule option)

Origin: Lavalette, a city in Midlan built near a lava field, The 'Field of Fire' and any source of great heat and destructive force is considered holy to the Inferknight league. The League is formed of Human and Dwarven Inferknights, dedicated to Lavalette's defense and the spread of the word of fire (burning what can be burnt). In their defense of a homeland Inferknights can be considered lawful, but their alignments must will NOT be lawful... (get that? they love their homes and won't burn THEM, but they must incorporate some chaotic element in their nature to mimic fire.) So alignment can be CG, CN, CE...

Chaotic Good inferknights will see fire as a cleansing element, and will preach strength through adaptation... they'd only set fire to something seen as weak or unclean.

Chaotic Neutral inferknights will be as fickle as fire, torching some things for kicks, and some things to teach.... but always at random.

Chaotic Evil Inferknights will always seem lusty for the destructive power of fire, and will always use it to teach a lesson, that being 'FEAR ME! FEAR FIRE!' CE Inferknights will also use fire to cleanse the world of what they see as weak.. which is just about anything they have a rational for torching.

Inferknights possess the following powers:

1. Detect Alignment of other Inferknights-- The neutrally aligned IK's
   will be seen as possible converts to the more radical alignments, the
   knights of opposed alignments will be seen as ignorant misfits abusing
   nearly divine power, and will be seen as hated enemies... (I told you
   they were flighty)

2. +2 bonus to saves-- based on the raw might of the fire burning in their
   hearts.

3. Immunity to all natural diseases-- The IK's inner fire is much too hostile
   to tolerate any kind of infection, this also applies to gross infestation
   (like eggs, worms, rot grubs) but the process of 'burning' these out will
   inflict 5 points of damage to the IK. Who will just love flaring up to
   purify himself... this is the only case of vulnerability to fire, and
   only because they allow it.

4. Touch of Fire: The Inferknight can deal 2 points of damage per level
   through his fiery touch at will, once per day. This heat is intense
   enough to set even moderately flammable items ablaze, bring a pot
   of water to boiling in one round, or merely crisp a troll really well.
   for purposes of regeneration it can be considered true fire.

5. Instill 'Cleansing lust'-- The Inferknight can cause a willing
   recipient to desire 'cleansing' as much as him, this translates to
   beserker rage (+2 to hit and dam, 2 point penalty to AC, all damage done
   recieved at combat's end, and a temporary protection from normal fire.)
   this lust lasts one round per level of the Knight... and can be used on
   the self. This rage can be instilled once per week per 5 levels of the
   Inferknight.

6. Aura of Warmth-- The IK radiates a field of warmth that can nullify the
   effects of natural cold, to a radius of 30 feet. So they make great
   arctic travelling companions... not to mention they scoff at cold
   weather. In already warm (or hot) regions they can nullify the field at
   will)

7. Fuel-- an Inferknight can boost the destructive capability of fire
   through an effort of will, boosting its damaging potential 10% per
   level, this applies to all fires (magical or not)... fire spells, and
   flaming weapons... fire reacts more vigorously for the IK.

8. An Inferknight with a 'Flame-tongue' wields it as a +5 weapon in all
   respects (undead, avians, what-not) In addition, he'll probably make
   a nasty mess in his shorts...
   "Hey.. a flaming weapon that never goes out! WOW! (burn)"

9. Burn Undead (Pun on 'turn' who caught it?) The IK has the ability to
   either instill horrid fear in the undead, or destroy them outright. In
   this case it functions as turning, though is not clerical in nature.
   a 'T' or succesful turn merely indicates that the undead realizes
   that the IK could destroy him, a 'D' indicates destruction via fire on
   the part of the undead... 'D*' just implies that he crisped a lot of them

10: Brother to Flames: at 5th level the IK is rapidly becoming a recognized
    force of fire, and recieves positive, friendly reactions from fire
    beings of all alignments... Fire Elementals will never attack him,
    Efreet think he's a snazzy fellow, etc... intelligent fire beasts
    might be coaxed into being his steed for a while (that is if they
    could be USED as steeds... A fire 'Animental' would be a good choice.

11: Immunity to fire-- Betcha were wondering when this would show up...
    in all cases, the IK is immune to fire damage of any kind. Cold
    attacks (magical) inflict 2 additional points of damage per die rolled.

12: Cast Priest Spells from Fire, Sun... Cast Wizard spells of Elemental
    fire school (see Tome of Magic) to 4th level in each. See paladin
    spell progression for spell quantity per level.

13: Cannot own more than 10 magical Items.. after all, fire is a jealous
    mistress. limited to...
    One suit of armor (preferably fire blackened plate types...)
    One shield (also fire blackened)
    4 weapons (obsidian items, flaming items prefered)
    and 4 'other' items (with rings of fire command at a premium.)

14: Cannot have more wealth than he can carry easily... isn't likely
    to place a high value on 'paper' money either... coins and gems
    will be prefered monetary units ('specially rubies)....

15: Where does that extra money go? Why.. to the construction of
    valuable wooden buildings of course... the Inferknight is quite happy
    helping out any charity... provided he can sneak back and burn down
    their efforts at some time.

16: Body of followers at 9th level, usually a compliment of fire mages
    pyromaniacs, and other 'hot-heads.'
Advances as a Paladin.

Reactions to other classes:
Fighters: great chaps...need some tutelage on the Divinity of fire tho.
Paladins: Feh... the ones that worship 'Forge' gods will be seen as kin.
Rangers: Ha ha.. right... like them almost as much as druids and it's reciprocated.
Mages: Lotta potential here.. you memorized fireball Fizban?
Priests: Depends on who you worship... lets hope it's not any Ice God... In which case you look a lot like kindling..
Thieves: make sure you add 'Arsonist' to your title.. otherwise.. Feh!
Druids: They tend to over react to each other... though CG IK's will probably form uneasy friendships with them... CE IK's will pretty much view druids as meddlesome 'Tree Huggers.'
Psi: Depends.. you know Molecular agitation? they'll love ya.