Agent

An Agent is a character that can be recruited by an awakening Old One to sow discord and chaos, prepare for the Old One's awakening, or otherwise do its bidding. They are the primary tools an Old One can directly command prior to awakening and as such integral to the game's strategy. Agents can move across the map, provide information on their surroundings, and may attempt Challenges, Rituals and Schemes to influence the world. They may also engage in combat with Heroes although one may often want to avoid this. The Old One can recruit one Agent per turn.

In the first devlog Belial and Karth start with the ability to command five Agents, Sisyphus four, and Azlan three.

Stats
These may be increased by finding items or by investing time and resources into the Agent through the Imbue system. Additionally, each Agent may have Traits which give them situational bonuses or maluses, alter how they interact with certain game systems and so on.

Agent-specific
All Agents share a few common statistics:
 * Strength, which helps the Agent perform Terrorize Challenges and is used in combat.
 * Infiltration, which helps the Agent perform Infiltration Challenges requiring stealth or political intrigue.
 * Arcana, which helps the Agent perform powerful Rituals and augment other actions.
 * Command, which helps the Agent in Recruit and Muster Challenges and allows the Agent to lead Minions; each Minion uses up 1 or more Command points while in use and will assist the Agent in combat, in Challenges, and may pass on a Trait to the Agent while under their command.
 * Labour is primarily provided by commanded Minions, and assists with Excavate and Construct Challenges (e.g. excavating a ruin).

Each agent also has access to a Scheme, a special Challenge only that Agent may attempt. An Agent that's available provides a passive benefit until activated.

Combat Stats

 * Defense. How many points are reduced from incoming normal attacks.
 * Health. An Agent whose Health is reduced to 0 is dead.

Agents lack classes and experience levels, which Heroes use to gain strength. They also lack will points, which represent a Hero's determination to fight on, not become a horribly corrupted shell sinking to any depth to serve the Old One, etc.

Fame And Recognition
Dark deeds bring Agents fame, and fame brings an increasing risk of a sword through the chest. Posting on the Bay 12 Games forum, King Dinosaur Games described Agents as having a time-bomb quality.

An Agent gains danger in the combat devlog. In POIs Danger is a stat that heroes use to consider whether they can tackle an obstacle, and which makes their questing more perilous. Posting on the Bay 12 Games forum, KDG mentioned Profile, which makes the Agent easier to find for Heroes. Giant Minions have high Profile. The Guildmaster has an increased Profile for being a public figure, and the Prophet has one for the way he just doesn't shut up about you.

The trailer features Agents receiving +14 fame for conquering a city, +7 fame for the start of a war, and +1 fame for infiltration. The combat devlog features +2 for a short battle that ends in the Agent fleeing, and +21 fame for a battle where one Hero betrays the others, one is turned into a minion, and Baron Greywind murders the rest. The Great Captain seizing control of a country's military and instituting a dictatorship is worth +34 fame in a screenshot.

Known Agents
In the 3/14/2015 update, King Dinosaur Games confirmed there are 26 agents in the game.

Starter Agents
These agents are available for recruitment at the start of the game.
 * The Prophet is automatically recruited at the start of most Scenarios. He cannot be Imbued but will automatically grow in strength along with his Old One's Ancient Power. His Scheme varies depending on the Old One chosen.
 * The Peddler is an itinerant merchant who can easily be swayed by even a weakened Old One and provides a low-visibility infiltration specialist. He can sell cursed weapons and poisoned potions to meddling Heroes. His Scheme, Prey upon Fear, allows him to manipulate public opinion and spark unrest.
 * The Rake is a disgraced and debauched nobleman who specializes in political intrigue. His scheme, Blood Will Flow commits random acts of heinous violence, creating high-profile clues that lead nowhere to distract heroes from your real plans.
 * The Outcast delved too deep and learned forbidden knowledge. She is the starting mage.

Recruitable Agents
You will need to meet some condition to recruit these agents.
 * The Afflicted has been promised an end to his curse in exchange for loyalty. He is good at infiltration in his normal form and can switch to his beast form to become a powerful combatant.
 * The Apostate is an agent linked closely to Religion.
 * The Baron is an undead lord and powerful warrior nursing immortal grudges. His scheme seizes control of all revolting provinces of his home culture.
 * The Biomancer specializes in bioengineering and interbreeding, crafting twisted horrors for the Dark One's armies.
 * The Black Goat is an unrevealed agent.
 * The Dreadnought is the other Twin. No further information but presumably he's a brutal warrior. Recruiting him raises the ire of The First.
 * The Dread Pirate is one of the primary naval focussed Agents. He is quite adapt at shutting down naval routes.
 * The False One is the Chosen One's dark mirror and can usurp the prophecy or deceive the Alliance.
 * The First is one of the Twins, an adept political maneuverer and one of the most powerful mages in the world. Recruiting her raises the ire of The Dreadnought.
 * The Great Captain is a legendary mercenary who can recruit minions easily and quickly to augment her skills. Her Scheme, Stroke of the Hand, is a careful gamble. If she can get infiltration on every mustered Commander in a nation, she can launch a coup and take control.
 * The Guildmaster is a specialist in intrigue and assassination, recruited by taking over a thieves' guild. His scheme, Hostile Takeover, automatically takes control of a guild currently at war with his own.
 * The Hordemaster is an Orc trainer and recruiter, who excels at leading Orc hordes into battle. His Scheme, Lessons in Bone, lets him sacrifice an elite Minion in order to pass its special combat ability on to another elite Minion.
 * The Hound is a peerless hunter. Any hero wounded by him grants him infiltration that wound has healed. His scheme, Seething Howl, saps the will of his quarry, eventually leading even the most stalwart to confront the Hound once and for all. Upon killing his quarry The Hound gains 1 Strength and deactivates, requiring a fresh expenditure of Ancient Power to resummon.
 * The Judge is an unrevealed agent.
 * The Lost is a gestalt of ancient souls trapped in chains, recruited by possessing a subdued hero. The Lost gains abilities based on the possessed hero and can also drain willpower and summon spirits.
 * The Matron is a queen of the outcast races and the ruler of the Court of Bone.
 * The Rictus is an unrevealed agent.
 * The Seeker is a sage who helped to seal the Dark One away in the distant past. An infiltrator and battle-mage, his scheme imbues agents, units, and neutral characters with special powers at great cost.
 * The Shadowmere is an ancient being of shadows sealed away in a forgotten tomb. He acts with impunity within his domain and has willpower-draining abilities. The Shadowmere can be awakened by meddling heroes or kingdoms and begin acting independently.
 * The Slaver Warchief is unlocked by taking over a merchant's guild specializing in the slave trade. Nothing has been heard of him since the Kickstarter and no art has been revealed in the Asset viewer, so he might be removed from the game.
 * The Speaker for the Dead is the leader of a Necromancer cabal, whose magic can raise legions of the undead. His Scheme, Scorn the Grave, binds a deceased Hero to the Speaker as a Minion.

Agents Removed From The Game

 * The Knight Errant can be pulled from the past moments before his death - he has a pool of time that counts down till he returns to his fate, he can use up that pool to take a variety of Chronomancy actions that would otherwise require complex rituals such as moving twice or going again in combat. However, if the heroes have Chronomancy they can use a ritual to banish him, not to mention having him use his abilities drops clues that can lead to the sages researching Chronomancy and now using it against you. Currently he's brokenly unbalanced, we're debating just taking away his time pool and giving him some passive abilities instead." The Knight Errant has been removed from the game, his all-too-unique ability set was handed out to a race of time-traveling lesser evils who will work for or against you.
 * The Artificer would help you create artifacts. But the Artificier was dissected and her abilities spread out through more mundane means (assembling the right artisans as minions)

Kickstarter Agent
As a Kickstarter Stretch Goal, backers received a choice of three new Agents, The Biomancer, The Devourer, and the The False One. That poll is closed. The Biomancer narrowly won with 280 of 597 votes, followed by the False One with 277. The Devourer received 40 votes. One of the Agent Tier backers has said he will use his reward to include the False One. The Devourer will make it to the game as a Lesser Evil.