There are no Epic Master Spies. The empire employs powerful divinations to ensure they know whenever anyone starts learning the art of the master spy. From that point on, those individuals are tracked relentlessly. If they developed new abilities, we would know. Surely, we would know.
Level BAB Fort Ref Will Special 1st +0 +0 +1 +1 Art of deception, master of disguise, sneak attack +1d6 2nd +1 +1 +1 +1 Glib lie, mask alignment 3rd +2 +1 +2 +2 Nonmagical aura 2/day, superficial knowledge 4th +3 +1 +2 +2 Concealed thoughts, quick change, sneak attack +2d6 5th +3 +2 +3 +3 Elude detection, slippery mind 6th +4 +2 +3 +3 Shift alignment 7th +5 +2 +4 +4 Sneak attack +3d6 8th +6 +3 +4 +4 Death attack, fool casting 9th +6 +3 +5 +5 Hidden mind 10th +7 +3 +5 +5 Assumption, sneak attack +4d6 11th +8 +4 +6 +6 Fortified Mind, Canny Defense 12th +9 +4 +6 +6 Fluid Identity 13th +9 +4 +7 +7 Need a Moment(1), sneak attack +5d6 14th +10 +5 +7 +7 Agent of Death 15th +11 +5 +8 +8 Need a Moment(2), Perfect Lie 16th +12 +5 +8 +8 Fluid Identity, sneak attack +6d6 17th +12 +6 +9 +9 Need a Moment(3), Friend to all 18th +13 +6 +9 +9 Trade Aura 19th +14 +6 +10 +10 Need a Moment(4), sneak attack +7d6 20th +15 +7 +10 +10 Consummate Mind
The following are class features of the master spy prestige class.
Weapon and Armor Proficiency: A master spy gains no proficiency with any weapon or armor.
Art of Deception (Ex)
A master spy adds her class level to all Bluff, Disguise, and Sense Motive checks.
Master of Disguise (Ex)
A master spy can create a disguise in half the time normally required. In addition, any penalties from assuming a disguise of a different gender, race, age, or size are reduced by 1.
Sneak Attack (Ex)
This ability is exactly like the rogue ability of the same name. The extra damage dealt increases by +1d6 at every third level (1st, 4th, 7th, 10th, 13th, 16th, 19th). If a master spy gets a sneak attack bonus from another source, the bonuses on damage stack.
Glib Lie (Su)
A master spy of 2nd level or higher can deceive truth-detecting magic. A creature using this sort of magic against the spy must succeed on a caster level check against a DC of 15 + the master spy’s class level to succeed (as if she were under the effect of a glibness spell); failure means the magic doesn’t detect the spy’s lies or force her to speak only the truth. This ability does not give the master spy the glibness spell’s bonus on Bluff checks.
Mask Alignment (Su)
A master spy of 2nd level or higher can alter her alignment aura to deceive spells that discern alignment (such as detect evil). She may choose to detect as any specific alignment, or to detect as no alignment at all. This ability does not protect against spells or effects that cause harm based on alignment. Masking her alignment aura is a standard action, and lasts until she changes it again or ends the effect.
Nonmagical Aura (Sp)
At 3rd level, a master spy can use magic aura twice per day, but only for the purposes of making an object appear nonmagical.
Superficial Knowledge (Ex)
A master spy gives the appearance of knowing more than she actually does. Starting at 3rd level, she can make untrained Knowledge and Profession checks pertaining to her cover or assumed identity as if she were trained and gains a bonus equal to half her level on these checks. For example, a master spy masquerading as a noblewoman can make untrained Knowledge (history) checks about the kingdom and Knowledge (nobility) checks about its noble and royal families as if she were trained, but she cannot make untrained Knowledge (nature) skill checks to identify herbs.
Concealed Thoughts (Su)
A 4th-level master spy can conceal her schemes from mind-reading magic. When a creature is using detect thoughts or similar magic to read her mind, she decides what surface thoughts her opponent detects, and her true surface thoughts remain private. This ability does not protect against mental attacks or mind-reading that delves deeper than surface thoughts. At 11th level, this ability applies to all mind reading.
Quick Change (Ex)
Starting at 4th level, a master spy can assume a disguise in only 2d4 (1d4 at 11th level) rounds by taking a –10 penalty on her Disguise check. This penalty drops to –5 at 8th level, and -0 at 12th level.
Elude Detection (Sp)
At 5th level, a master spy can befuddle divinations used against her as if she were under the effect of a nondetection spell with a caster level equal to her character level. She can suppress or resume this protection as a standard action. If dispelled, the spy cannot resume the nondetection for 1d4 rounds.
Slippery Mind (Su)
At 5th level, a master spy can slip away from mental control. This functions as the rogue advanced talent of the same name. If the spy has the slippery mind ability from another class, these abilities stack, but she can still only use slippery mind once per round.
Shift Alignment (Su)
Starting at 6th level, a master spy’s control over her aura improves. When she assumes a false alignment, she can choose to have all spells and magic items affect her as though she were that alignment; this includes helpful and harmful effects. For example, a neutral good master spy can shift her aura to lawful evil so she can pass through a doorway that shocks creatures that aren’t lawful evil; if hit by holy smite with this shifted aura, she takes damage as if she were evil. A master spy can change her alignment aura from a masked alignment (as per her 2nd-level class feature, where effects still function based on her actual alignment) to a shifted alignment (as per this ability, where effects function based on her assumed alignment) as a standard action. Shifting her alignment aura is a standard action, and lasts until she changes it again or ends the effect.
Death Attack (Ex)
At 8th level, a master spy learns the art of killing or paralyzing a foe with a careful strike. This ability functions as the assassin’s death attack ability. If the master spy has levels in another class that grants the death attack ability, these levels stack with her master spy level to determine the DC of her death attack, even if she has not yet reached 8th level as a master spy.
Fool Casting (Su)
A master spy of 8th level or higher can trick an opponent into believing that she has been charmed or dominated. When the master spy succeeds at a saving throw against a magical effect that provides ongoing control (such as charm person, dominate person, or a vampire’s dominate ability), she can allow the spell to take partial effect. To the caster, it appears that the spy failed her saving throw, but the spy is not under the caster’s control. If the spell provides a telepathic link, it functions normally, but the spy is under no obligation to follow the caster’s commands. The master spy can dismiss a fooled spell as a standard action. Fooled casting can be used when the spy succeeds at a subsequent saving throw against an ongoing effect, such as that granted by slippery mind.
Hidden Mind (Sp)
At 9th level, a master spy gains the benefit of a constant mind blank spell at a caster level equal to her character level. The spy can suppress or resume this protection as a standard action. If dispelled, the spy cannot resume the mind blank for 1d4 rounds.
The ultimate ability of the master spy is to take over another persona entirely, making it her own. As a full-round action, the spy can touch a helpless creature and shift her aura to that of her target. This confuses divination effects and spells, even ones as powerful as discern location, such that they register the spy as being the creature she has touched. This ability is not proof against the actions of deities or similarly powerful beings. The assumption of an identity lasts until the master spy ends it (a standard action) or she uses the ability on another creature.
At 11th level, a Master Spy gains mental resiliency to avoid certain attacks. If she makes a Will saving throw against an attack that has a reduced effect on a successful save, she instead avoids the effect entirely. A helpless Master Spy does not gain the benefit of the Fortified Mind ability.
At 11th level, a Master Spy is never quite where she appears to be. This works as the duelist ability of the same name.
Fluid Identity (Su)
At 12th level, whenever a Master Spy is targeted by an effect which depends on alignment, she may choose what alignment she is considered for that effect as a free action. At 16th level, this ability also applies to type and subtype. For example, after walking through an anti-life shell due to being a construct, she would ignore the effects of Blasphemy and Holy Word due to being evil and good, respectively; be healed by a harm spell by virtue of being undead, and ignore a slay living, as constructs are not alive. (Note that she is not actually mindless, this would not protect her from dominate monster, though Hidden Mind would)
Need a Moment (Sp)
At 13th level, a Master Spy may use Time Stop as a spell-like ability once per day, plus one additional time per two levels beyond 13th. At 19th level, this becomes Time Evasion (1d4+1 minutes of Time Stop).
Agent of Death (Ex)
At 14th level, once per round when she deals damage with a sneak attack, a Master Spy may perform a death attack, forcing the victim to make a fortitude save (DC 10 + her Master Spy level + her Int modifier) against death or (at the choice of the Master Spy) be rendered helpless and unable to act for 1d6 + 1/level rounds.
Perfect Lie (Su)
At 15th any method – applied to the Master Spy or her statements – used to determine the truth of those statement returns an answer of her choice. This ability is not proof against the determined efforts of deities.
Friend to all (Sp)
At 17th level, a master spy can confuse all onlookers as to her true allegiance. Each creature which can perceive her must make a will save (DC 10 + her Master Spy level + her Int modifier) or consider the Master Spy their ally for 1 hour/Master Spy level. This is a mind-effecting effect. She can use this ability 3 times per day.
Trade Aura (Su)
At 18th level, the Master Spy’s control over auras allows her to exchange them permanently. As a full round action, the spy can touch a helpless (or willing creature) and exchange auras with them. This functions as Assumption, but the target also gains her Aura. This effect is permanent and persists even if the Master Spy uses Trade Aura again – in which case the Aura of the first target shifts to the second target, the Master Spy gains the Aura of the second target, and the first target retains the Master Spy. This ability is not proof against the determined efforts of deities. The effect can only be undone by a master spy finding and returning the original aura, or the direct intervention of a deity.
At 20th level, whenever she is affected by a mind-effecting effect, or one which allows a will save, a Master Spy may choose among all possible effects of the spell. For instance, if she may choose to pass any will saving throw, or she may choose the answer returned by any applicable divination.