From Compendium of Worldly Lore
Incantifier is interesting because it provides you the benefits of not needing to eat drink or breathe but you're not quite undead. You also get to absorb spells in order to heal yourself and you have spell resistance and eventually can do so even from magical items. Most notably though is that this class sort of functions as a self-sustaining wizard being able to heal yourself by leeching off others and being able to rechannel the sequestered energy to get back your spell slots, this is a near villainous gameplay loop that you'll find yourself in.
Role: Spell DPS
Characteristics: Not quite living casters that consume spell power to survive
Source: Dragon Magazine #339
Game Rule Information
The Incantifier has the following game statistics.
Abilities: Constitution for keeping concentration, Intelligence for your likely casting stat and skill points. Dexterity is also helpful for staying alive
Alignment: Any Nongood
Hit Die: d4
Starting Gold: N/A
Class Skills
The Incantifier's class skills are Concentration (Con), Craft (Int), Decipher Script (Int), Knowledge (arcana) (Int), Knowledge (history) (Int), Knowledge (the planes) (Int), Listen (Wis), Profession (Wis), Search (Int) Spellcraft (Int), and Spot (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 Incantifier.
Weapon and Armor Proficiency: A Incantifier is proficient with whatever they were already proficient with prior to taking levels in this class.
Arcane Body Ex: An incantifier's body ceases to function as most living creatures' do, coursing with unbridled magical energies. While he is not undead, elements of his existence are fundamentally warped by the arcane energies he relies upon to sustain him.
An incantifier does not heal naturally, nor can he be healed through normal magical means. Only through draining magic using his spell eater or spell leech ability can an incantifier replenish his physical health. However, an incantifier no longer has any need to eat, drink, or sleep and does not take penalties from neglecting these need. In addition, an incantifier no longer takes any negative effects from aging and has no maximum age.
Spell Eater I Su: An incantifier depends on magic to live and must absorb arcane magic to heal. If an arcane spell or spell-like ability does not beat an incantifier's spell resistance, the incantifier absorbs the magic and heals 1d4 hit points per spell level. Spells that ignore or overcome the incantifier's spell resistance affect him as normal. The incantifier decides whether or not his spell resistance affects spells he casts on himself, either benefiting from the spell or healing as he chooses.
When a spell is negated by the incantifier's spell resistance, he may choose to use either the spell eater or spell leech ability, but not both.
Spell Resistance Su: An incantifier gains spell resistance equal to 20 + his incantifier level. This spell resistance supersedes any other spell resistance, including from race, items, or spells.
Metamagic Feat: At 2nd and 4th level, the incantifier may choose a metamagic feat as a bonus feat.
Spell Leech I Su: At 3rd level, an incantifier can channel absorbed arcane energy back into his own magic. If an arcane spell or spell-like ability does not beat the incantifier's spell resistance, the incantifier regains a spell of the absorbed spell's level that he has already cast that day or regains a used spell slot of the appropriate level. If the incantifier has his full complement of spells, and thus has no cast spells or used spell slots, he cannot benefit from this ability. For example, if a wizard incantifier's spell resistance negates a lightning bolt, he can restore a single 1st-, 2nd-, or 3rd-level spell he had previously cast, regaining it as if he had never cast it.
When a spell is negated by the incantifier's spell resistance, he may choose to use either the spell eater or spell leech ability, not both.
Spell Eater II Su: At 3rd level, the incantifier can heal himself using arcane magic drained from single-use or charged magic items. This ability requires a full-round action and can only be used on an item the incantifier is holding. Using spell eater on a potion or scroll destroys the item but heals 1d4 hit points per spell level of the item destroyed. Using this ability on a charged magic item drains 5 charges and heals the incantifier of 1d4 hit points per spell level of the highest-level spell the item possesses. The incantifier cannot be healed more than his maximum number of hit points. This ability has no effect on multiple-use items without charges, like magic weapons, armor, or rings.
Spell Leech II Su: At 5th level, an incantifier can siphon charges from a staff or wand to regain spells he has already cast. This ability requires a full-round action and can only be used on an item the incantifier is holding. Using this ability drains 5 charges from the magic item and replaces a cast spell equal to or less than the highest-level spell the staff or wand holds. Upon draining these charges, the incantifier regains any spell of up to the affected spell's level that he has already cast that day or regains a used spell slot of up to the appropriate level. For example, a wizard who has cast his only fly spell for the day (a 3rd-level spell) may drain 5 charges from his wand of fireballs (another 3rd-level spell) to regain fly or any lower-level spell he has cast.