From Compendium of Worldly Lore
Some people just don't know any better; they are easy prey for the Lying Darkness. Others are much more corrupt to begin with, know that they are servants of evil, but just don't care. The Tainted Shadow is a rogue or ninja-oriented prestige class for those who just can't help themselves when it comes to stealthy power.
Role: DPS
Characteristics: Tainted stealth based adventurers with shadow powers
Source: Bloodspeakers
Game Rule Information
The Tainted Shadow has the following game statistics.
Abilities: Constitution for the Concentration checks you need to make, Dexterity for being incredibly sneaky
Alignment: Any
Hit Die: d6
Starting Gold: N/A
Class Skills
The Tainted Shadow's class skills are Appraise (Int), Concentration (Con), Craft (Int), Disguise (Cha), Gather Information (Cha), Hide (Dex), Innuendo (Wis), Knowledge (all taken individually)(Int), Listen (Wis), Move Silently (Dex), Profession (Wis), Sense Motive (Wis), Search (Int), Spot (Wis), and Swim (Str).
Skill Points at 1st Level: (4 + Int modifier) × 4
Skill Points at Each Additional Level: 4 + Int modifier
Class Features
All of the following are class features of the Tainted Shadow.
Weapon and Armor Proficiency: A Tainted Shadow is proficient with whatever they were already proficient with prior to taking levels in this class.
Shadow Lover: A tainted Shadow gains a +4 corruption bonus to all attempts to Hide. This bonus does not apply when an area is protected by anything that wards off Taint (such as jade or Protection From Taint)
Aversion to Daylight: At 2nd level, the tainted shadow begins suffering a -1 penalty to attacks and saving throws when in full sunlight or within the boundaries of a Daylight spell.
Shadow Touch Ex: At 3rd level, the tainted shadow's touch chills living creatures. The tainted shadow's unarmed damage increases to 1d4 cold damage and also inflicts a temporary1 point Strength loss per successful touch attack.
Bonus Feat: At 4th level and again at 8th, the tainted shadow gains an additional feat.
Whispering Darkness Su: At 5th level, a tainted shadow can learn what is happening in regions of shadow very far away, as the kansen, undead shadows and other corrupt kami whisper the secrets of creatures and things hidden in shadow. To use this ability requires a successful Concentration check; the DC varies by distance, as shown in Table 1-2.
If the check is successful, the tainted shadow sees and hears through his or her shadow helpers as if he had cast Clairvoyance/Clairaudience (per the spell). Scrying through shadows can be detected and blocked by any method that hinders kami or divination spells.
Wraithform Sp: At 7th level a tainted shadow can literally become a wraith, as described in the Wraithform spell. Unlike the spell, someone with enough physical stamina can maintain the effect almost indefinitely. The spell's base duration is one minute per class level of the tainted shadow. Once that duration increment ends a Concentration check (DC 5 initially) is required. If the check succeeds, the tainted shadow retains its insubstantial form. If not it is immediately returned to physical form.
Summon Shadows Su: At 9th level, a tainted shadow can summon the undead known as shadows once per night, by taking a full-round action to call to darkness. A swarm of 3d12 shadows answer the call, one round later and obey the tainted shadow for a number of rounds equal to his Taint score. The tainted shadow can also use this ability during daylight hours but summons only 1d4 shadows on clear sunny days or 2d4 on cloudy days.
Liquid Darkness: At 10th level, the tainted shadow is almost entirely beholden to the darkness but just barely able to maintain control. The tainted shadow can shapeshift at will into a shadow form. This is an incorporeal shift that takes all worn and carried items with it.
At the same time, the call of darkness becomes more difficult to resist. Every time the character casts a maho spell or uses the shapeshifting ability, he may lose control of his increasingly tainted body. The character is entitled to a Will save with a DC equal to 10 + his Taint. If the check fails, he is overcome by the kansen's wiles and permanently possessed, effectively becoming an NPC.
The tainted shadow often becomes a maho-bujin when his or her taint score exceeds 50.