“I study what I do not learn and see what is not there. My craft is of naught and has brought me power. However, if my work is a shadowy nothing, from where can this power come forth?”
-Serez Kezren, Initiate of the Seven Enigmas

Initiates of the Seven Mysteries are far unlike other mystery-users. Rather than improve their power over shadows, they study the mechanics of the shadows themselves, and by extension, the mechanics of all of reality. Those who plumb into the mysteries behind mysteries find themselves weaving their shadow magic in unimaginable ways.

Initiates require relatively little to start along their track, other than the knowledge of how to and the concentration to manipulate their mysteries, accompanying some talent with the mysteries in question. Although a few cultists can take up this path, the number of shadowcasters who do so outnumber them immensely.

Entry Requirements
Skills: Concentration 10 ranks, Knowledge (arcane) 10 ranks, Knowledge (the planes) 10 ranks
Shadowcasting: ability to cast at least 2 initiate-level mysteries.

Level   Base     Fort   Ref    Will   Special                           Mysteries
        Attack   Save   Save   Save

 1       +0       +0     +0     +2     Enigmas in mysteries              +1 level of existing mystery-using class
                                       The First Enigma (Imitation)
 2       +1       +0     +0     +3     The Second Enigma (Illusion)      
 3       +1       +1     +1     +3     The Third Enigma (Manipulation)   +1 level of existing mystery-using class
 4       +2       +1     +1     +4     The Fourth Enigma (Reflection)    
 5       +2       +1     +1     +4     The Fifth Enigma (Form)           +1 level of existing mystery-using class
 6       +3       +2     +2     +5     The Sixth Enigma (Shadow)        
 7       +3       +2     +2     +5     The Seventh Enigma (Existance)    +1 level of existing mystery-using class
Class Skills (2 + Int modifier per level): Concentration, Craft, Knowledge (arcane), Knowledge (the planes), Profession, Spellcraft.

As you advance, your actual shadowcasting may degrade but your power with mysteries remains as strong as ever.
Mysteries: at each odd level, you gain new mysteries and an increase in aster level as if you had also attained a level in a shadowcasting class to which you belonged before adding the prestige class level. You do not, however, gain any other benefit a character of that class would have gained. If you had more than one shadowcasting class before becoming an Initiate of the Seven Enigmas, you must decide to which class to add each level for the purpose of determining mysteries per day, caster level, and mysteries known.
Enigmas in Mysteries (Su): An Initiate of the Seven Mysteries finds power through the very mechanics of mysteries. Manipulating mysteries in this way is quite taxing. Whenever an enigma is utilized, they must succeed on a concentration check (dc 10+1/previous enigma successfully utilized that day). With a failure, the enigma fails to manifest and the daily use is wasted. Each enigma is a supernatural ability.
The First Enigma (Imitation): The first mystery, often not noticed by onlookers, is that of imitation. After all, Shadow magic is nothing more than use of an objects shadow to control the object in question. Once per day per class level, by sacrificing a daily use of any mystery, the Initiate of the Seven Mysteries can gain an extra daily use of any mystery of a lower level. This extra use lasts for 24 hours or until used.
The Second Enigma (Illusion): The first, and most basic allusion to shadow magic invariably appears in the power of illusion, giving form to imitation. Once per day per class level, by sacrificing a daily use of any mystery, the Initiate of the Seven Mysteries can imitate the effects of any illusion spell at least 1 spell level lower, other than those with the shadow subschool.
The Third Enigma (Manipulation): The third mystery is that of manipulation, providing versatility for stagnant illusions. Once per day per class level, the Initiate of the Seven Mysteries may apply one metashadow feat to a mystery without using a daily use of that metashadow feat or increasing its casting time.
The Fourth Enigma (Reflection): The fourth mystery is that of reflection, manipulated to provide an effect of equal power. Once per day per class level, on a round after casting a mystery, the Initiate of the Seven Mysteries may spend a full-round action to repeat the casting of that mystery (which apparently emanates from your shadow), without the expenditure of an additional daily use.
The Fifth Enigma (Form): The fifth mystery is that of form, allowing prolonged manipulation of reflection. Once per day per class level, the Initiate of the Seven Mysteries can cast a mystery as an extraordinary ability, adding 2 to its save DC.
The Sixth Enigma (Shadow): The sixth mystery is that of shadow, reflection given form. Once per day per class level, the Initiate of the Seven Mysteries can cast a mystery as a move action.
The Seventh Enigma (Existence): The final mystery is that of existence, covering both shadow and its reflection. Once per day per class level, as an immediate action, the Initiate of the Seven Mysteries can ignore the effects of a 3rd-level or lower spell or mystery for one round. If its duration ends or if its area is vacated by the end of that round, it is completely ignored. Otherwise saving throws and spell resistance (if any) are checked for at the end of the round.

Your ability to warp shadow magic has given it an entirely new feel in your hands. Just as the Plane of Shadow shifts, so does its magic. There is nothing wrong with what you do. You are simply directing the flow of the plane of shadow, to a lesser extent. These abilities are normally learned but have appeared naturally in some promising young prodigies.
Shadow-based organizations, as a whole, are confused about Initiates of the Seven Enigmas. They willingly let their shadowcasting degrade but increase their manipulation of it. Some view this view as intricacy while other (more ignorant) groups consider this laziness.
Initiates of the Seven Enigmas, more than anywhere else, are found as teachers, due to their scholarly outlook. In this niche, other shadow magic users accept them almost universally.

An Initiate of the Seven Enigmas makes for an interesting combatant. Due to a slightly lacking supply of mysteries, many assume that they are less versatile. The abilities they receive in return for this degradation, however, could not prove this viewpoint more false.
As you progress, your ability to modify and empower your mysteries becomes more powerful, and versatile. You must remember, however, not to take on more enemies than you can take, however, as each successive use of your abilities become harder and harder to release.

Your ways are almost guaranteed to have been learned ones. It is also likely that you learned from another Initiate of the Seven Enigmas. Some tomes describe the processes well enough to be used alone, however, and even others make purely intuitive leaps after observing movement on the plane of shadow over long periods of time.
Continuing advancement needs constant practice, study, and vigilance. Although you may not learn the strongest of abilities any time soon, you have happened upon a wellspring of new abilities.
Once you have started along this path, the mysteries taken count for much more than normal, due to your degraded progression. Other than this small issue however, the only things that you’ll truly need will be items and feats to help your concentration skill.

As a respectable sage or teacher within an organization, you might find loose ends of yours being met for you. Alas, magic items are often not provided. As a student of shadow, any opportunity to study its mechanics, such as in magic items utilizing mysteries, it a worthy investment. As you are still reliant upon your shadowcasting to protect you, items that increase your charisma and intelligence (or wisdom, for cultists) scores are vital. As you are likely to have relative frailty, any item that enhances your defenses is another boon.

“The search for such knowledge as the workings of existence is a worthy endeavor. What worries me is that she, of all people, may succeed.”
-Glimdon Salagger, Foruton Librarian

The Inititiates of the Seven Enigmas allows the DM to showcase both the intellectual-side and alien-mindset behind shadow magic.

Initiates of the Seven Enigmas live in much the same ways as any other wizards. They must continue to learn their mysteries through constant study. To keep their minds steady, they often meditate. The only unusual part of their studies is the practicing of their enigmas. Although not necessary, most Initiates of the Seven Enigmas try to use each of their enigmas once after regaining their mysteries, to help them validate their studies. Once an Initiate of the Seven Enigmas finds a decent source of knowledge, they are loathe to leave it, and sometimes remain even long after their nature is revealed.

Initiates of the Seven Enigmas rarely choose to take notoriety directly, rather gaining it through those who they have provided tutelage. One, Totalas Grimp, educated many members of the Parliament of Shadow. For this reason, he is probably one of the most well-known Initiates.

Initiates of the Seven Enigmas rarely join a shadow organization. At least, not officially. Unofficially however, they are seen as unparalleled sources of knowledge. For this reason, many Initiates intrude upon the hospitality of several organizations over their career. This situation has led to a relatively stable symbiotic relationship between the two. Initiates of the Seven Enigmas help shadow organizations by passing on rumors or assisting in the teaching of new recruits. Meanwhile, the initiate benefits from safety, a roof above their heads, and a good steady of knowledge.

Most people respond to an Initiate of the Seven Enigmas in the same way that they would respond to any sage or philosopher. If their nature is discovered, less changes than one would expect. As the Initiate normally keeps to herself, most townsfolk have no problem with harboring them. In addition, due to an Initiate’s determination to learn, they are likely to ignore any sign to leave that falls short of direct violence or persecution. Even the most hardcore of priests thinks of them (incorrectly) as a frail practitioner of iffy magic, and therefore of little threat. Even so, it is easier to capture the one teacher than the many pupils.

Characters with ranks in Knowledge (arcane) or Knowledge (the planes) can research Initiates of the Seven Enigmas to learn more about them. When a character makes a skill check, read or paraphrase the following, including the information from lower DCs.
DC 10: The Initiate of the Seven Enigmas is a philosopher among shadowcasters.
DC 15: The Initiate of the Seven Enigmas sacrifices a bit of power from their Shadow Magic to gain more versatility with it.
DC 20: The Initiate of the Seven Enigmas manipulates their powers through loopholes in reality called enigmas, which they activate through sheer force of will.
A bardic knowledge check or a Gather Information check can reveal the same information as these Knowledge checks, but in each case the DC is 5 higher than the given value.

Initiates of the Seven Enigmas are the thinking intellectuals of Shadow Magic, studying it rather than taking it for granted. They are best used not for introducing shadow magic, but as a surprise when shadow magic’s novelty wears thin. The Initiates, remember, can modify the very nature of the mysteries they use, enough so to surprise any party.
With the unusual and thoughtful nature of this Prestige Class, this may prove to be the aspiration of a Shadowcaster or Cultist PC. The creativity that this class allows is an invaluable addition to any party.

With a few slight tweaks, the Initiate of the Seven Enigmas could be dedicated to shadow spells rather than to shadow magic. At an even more rudimentary scale, they could be dedicated to the mechanics of shadow magic or even to the mechanics of magic as a whole.

To be used at peak efficiency, the Initiate of the Seven Enigmas should only be thrown at the party once the rules of shadow magic have been established, only to have them knocked down by their new foe. Only after watching the Initiate do they realize the truly morphic power of shadow.
EL 10: Serez Kezren is currently occupying a small town’s library. Although they know her nature and have made their wishes for her to leave quite clear (to the point of a few failed assassinations), she is determined to remain until her studies are complete.
Serez Kezren CR 10
Female elf Shadowcaster 7/Initiate of the Seven Enigmas 3
TN Medium humanoid (elf)
Init +1; Senses Low-light vision; Darkvision 30 feet; Listen +1, Spot +1
Languages Common, Elven, Sylvan, Gnome, Draconic, Goblin
AC 19, touch 13, flat-footed 18
hp 34 (10 HD)
Fort +7, Ref +5, Will +8
Speed 30 ft. (6 squares)
Melee +1/Masterwork Quarterstaff +6 (1d6+1/1d6)
Ranged Light crossbow +6 (1d8/19-20)
Base Atk +5 ; Grp +5
Special Actions Shadowcast, Still Mystery, Extend Mystery, Enlarge Mystery, Empower Mystery, Maximize Mystery, Quicken Mystery, The First Enigma (imitation), The Second Enigma (Illusion), The Third Enigma (Manipulation)
Combat Gear 3 orbs of shadow (apprentice 1st), 3 potions of cure moderate wounds, Shadow Maniple, Ring of Nullification, Gem of Night
Mysteries Known (CL 9th)
Initiate Paths
4th—Bolster (spell, 1/day), Shadow Evocation (spell, 1/day), Shadows Fade (spell, 1/day)
Apprentice paths:
1st—Turbulent Dreams (spell-like, 2/day), Cursed Flame (spell-like, 2/day), Steel Shadows (spell-like, 2/day), Carpet of Shadow (spell-like, 2/day), Dusk and Dawn (spell-like, 2/day), Life Fades (spell-like, 2/day)
0—umbral hand (supernatural, 3/day), Mystic Reflections (supernatural, 3/day), Caul of Shadow (supernatural, 3/day), Arrow of Dusk (supernatural, 3/day)
Abilities Str 10, Dex 13, Con 10, Int 17, Wis 8, Cha 14
SQ Able to notice secret of concealed doors, Sustaining Shadow (eat 1 meal/week), Enigmas In Mysteries
Feats Shadowcast, Still Mystery, Empower Mystery, Extend Mystery, Maximize Mystery, Quicken Mystery, Enlarge Mystery
Skills Concentration +13, Intimidate +15, Knowledge (arcana) +16, Knowledge (the planes) +16, Spellcraft +16
Possessions combat gear plus +1/Masterwork Quarterstaff, Light Crossbow with 20 bolts, Cloak of resistance +1, 75 gp.