Your attempt to transition into unlife has gone horribly awry and your soul is trapped. Lich corruption also works for becoming another sort of corporeal undead (except ghouls and vampires, which have their own corruptions).
This corruption originates from an unsuccessful attempt at lichdom. You might have lacked sufficient power or used a flawed phylactery. If you’re not a spellcaster, you could have been an innocent bystander or become corrupted upon destroying a particularly powerful lich’s phylactery.
Lich corruptions are rarely stable, and cause incredible mental and physical strain. Whenever you fail a saving throw against a necromancy effect, learn how to cast a new spell or spells, or are exposed to 25 points of negative energy damage or more from a single source (whether it heals or harms you), you must succeed at a Fortitude save (DC = 15 + your manifestation level) or become spiritually disjoined. You also need to make a saving throw whenever anyone successfully casts the death ward spell on you. After a failed save, your spirit and body disconnect, leaving your corporeal form helpless and your mind trapped within the Negative Energy Plane. This state lasts for 1 hour per manifestation level; if you are killed during this time, you rise 24 hours later as a wraith under the GM’s control.
Corruption Stage 1: The first time you recover from this disconnected state, you return diminished, taking a permanent –2 penalty to your Charisma score, and your alignment shifts one step toward evil.
Corruption Stage 3: The third time this happens, you die and your soul is consumed by the Negative Energy Plane.
Removing the Corruption
Curing lich corruption requires great acts of purification, such as being exorcised by a powerful cleric, bathing in sacred springs, or creating a phylactery of your own into which to expel the lich corruption.
The following are manifestations of the lich corruption.
Your touch racks the living with pain.
Prerequisite(s): Manifestation level 4th, death’s caress*.
Gift: Once per day per manifestation level, you can make an agonizing touch as a standard action. A living creature hit by this touch attack must succeed at a Fortitude save or be staggered for a number of rounds equal to 1/2 your manifestation level.
Stain: Both of your hands wither to nearly skeletal appendages, and your emotions dim towards the coldness of undeath. You take a –2 penalty on attacks with manufactured weapons. Your spells with somatic or emotion components have a 5% failure chance. This stacks with any spell failure chances you incur from other sources.
Entropy seeps from your body.
Prerequisite(s): Manifestation level 4th, deathless*.
Gift: Any living creature that ends its turn adjacent to you takes 1 point of negative energy damage for every 2 manifestation levels you have.
Stain: Animals are startled by your presence, worsening their starting attitudes toward you by one step. Any animal companion you have abandons you when you acquire this stain. Whispering voices fill the air around you, begging for release or cursing your existence. Any creature that succeeds at a DC 20 Perception check can hear these whispers, which might alert it to your presence if you’re using Stealth.
Your body takes on a deathly likeness.
Stain: Your flesh tightens, turning corpselike and gray as your body rots. You take a –2 penalty to your Constitution.
You are inured to negative energy.
Gift: You gain a +2 bonus on saving throws against spells and effects that work only on living creatures.
Stain: You are healed by negative energy and harmed by positive energy as if you were an undead creature.
Your touch drains the warmth of life from others.
Stain: The flesh from one of your hands rots away, leaving it a blackened, skeletal claw. Spells that detect undead sense you, though the peculiar result they return informs the caster that you’re still a living creature. Other spells and effects don’t treat you as undead.
You become emaciated and nearly skeletal.
Prerequisite(s): Manifestation level 4th, cadaver’s countenance*.
Stain: You take an additional –2 penalty to your Constitution score and are affected by spells and abilities (including bane and favored enemy) as if your creature type were undead. This doesn’t grant you the immunities of undead creatures, nor does it make you immune to effects that target living creatures or change how negative and positive energy affect you.
You can wrench your soul from your body to possess another.
Prerequisite(s): Manifestation level 7th, bleak aura*, deathless*.
Gift: You can touch a living creature as a standard action and force your soul into its body. If hit by this touch attack, the target must succeed at a Will save (DC = 15 + your manifestation level) or be affected by possession. You can possess creatures for a number of minutes per day equal to your manifestation level. These minutes don’t need to be used consecutively, but must be spent in 1-minute increments.
A failed attempt costs 1 minute of use and renders your target immune to your malevolence for 24 hours. Your body is helpless while you possess another creature, and if it is destroyed you die when the duration of malevolence ends.
You can use malevolence while in another creature’s body to transfer your soul again (following the same rules for casting possession while in a body that’s not your own).
Stain: Your spirit is untethered from your body. You roll twice and take the lowest result on saves against spells that imprison or target your soul, such as magic jar and trap the soul, as well as against positive energy effects. If you drop below 0 hit points, your soul leaves your body and you instantly die.
You can animate the dead with your necromantic power.
Prerequisite(s): Manifestation level 6th, agonizing touch*, death’s caress*.
Gift: You can cast animate dead at will as a spell-like ability with a caster level equal to your character level. You must provide the material components, and you take 2 points of Charisma drain for every creature you animate. If the drain is removed or you avoid taking it, the animated creature is immediately destroyed (you choose which creatures are destroyed if some but not all drain is removed). Conversely, the Charisma drain from animating a creature is instantly removed when that creature is destroyed. You still must abide by the usual Hit Die limits of animate dead.
Stain: Your emotions are nearly a thing of the past. You can’t benefit from morale bonuses or bardic performances.
You have gained unusual insights into necromancy.
Prerequisite(s): Manifestation level 2nd, ability to cast spells.
Gift: You can add one necromancy spell from the sorcerer/wizard spell list to your spellbook, familiar, or list of spells you can prepare or to your spells known. This spell must be of a level you can cast. A spell learned in this fashion is treated as though it were on your class spell list. If you normally cast your spells from the sorcerer/wizard spells list, you can add a necromancy spell from the cleric or witch spell list instead.
Special: You can gain this manifestation multiple times.
Each time you gain the gift, you gain a different necromancy spell, and each time you gain the stain, the penalties stack.
Pathfinder Roleplaying Game Horror Adventures © 2016, Paizo Inc.; Authors: John Bennett, Clinton J. Boomer, Logan Bonner, Robert Brookes, Jason Bulmahn, Ross Byers, Jim Groves, Steven Helt, Thurston Hillman, Eric Hindley, Brandon Hodge, Mikko Kallio, Jason Nelson, Tom Phillips, Stephen Radney-MacFarland, Alistair Rigg, Alex Riggs, David N. Ross, F. Wesley Schneider, David Schwartz, Mark Seifter, and Linda Zayas-Palmer.