Dunamancy

 is the ancient and esoteric study of the magic of dunamis.

Description
Dunamis is "the primal magical energy of potentiality and actuality, an anticipatory arcane force that helps shape the multiverse and might very well be what holds its elements together, like an infinite web of unseen tethers. ... Those who study to control and tap into this near-invisible power can subtly bend the flow of time and space by controlling the forces of localized gravity, peering into possibly timelines to shift fate in their favor, and scattering the potential energy of their enemies to rob them of their potency."

Known Spells

 * Fortune's Favor
 * Gift of Alacrity
 * Gravity Sinkhole
 * Immovable Object
 * Magnify Gravity
 * Resonant Echo
 * Tether Essence

While spending down time in Archive of the Cobalt Soul in Zadash, Caleb Widogast researched methods of controlling time. He discovered information about some newer arcane experiments being conducted by the Soltryce Academy in Rexxentrum. A newer magical energy seems to have been discovered, or possibly rediscovered, from the Age of Arcanum. This energy is being referred to by the Soltryce mages as "Dunamis". Other than that, there's very little information: anything else is the proprietary knowledge of the Academy.

While searching the basement of Yeza Brenatto's apothecary in Felderwin, the Mighty Nein find notes of a Cerberus Assembly researcher. The Assembly has been doing experiments with a Beacon. The "dunamis field" from the experiments has covered large areas, causing people to sometimes feel sluggish and sometimes move at unnaturally fast speeds. The Kryn Dynasty of Xhorhas has the ability to use Dunamancy to manipulate gravity, entropy, and time. The Kryn have been researching its use for centuries in Ghor Dranas.

It has been difficult for the Cerberus Assembly to create an object that can sustain the energy of a dunamis field. Yeza Brenatto has been working with the Cerberus Assembly and distilled one vial of dunamis. They have plans to make more once they can remove the Beacon from the process. The notes say that Trent Ikithon has found some students who show signs of being skilled at Dunamancy.

After emerging from the worm tunnels into Xhorhas, the Mighty Nein were ambushed by a pack of gnolls, a Kryn Dynasty warrior, and a mage. The mage cast two dunamancy spells- Compress Gravity and Vacuum Blast.

Essek Thelyss teaches Caleb two dunamancy spells during his visit in the episode. He mentions spells that revolve around "density, gravity, things that manipulate the relationship between objects or are you more interested in the bending of fate, destiny or do you wish to find ways to sap and scatter the potentiality of your enemy." In the end, Caleb chooses to learn about fate and Essek teaches him two dunamancy spells.

After visiting the Scourger captive upon their return once again to Xhorhas, and accepting the mission to locate the missing Luxon Beacon, Caleb persuades Essek to teach him two more Dunamancy spells: Immovable Object and Resonant Echo.

Trivia

 * Dunamancy and its unique spells are a homebrew creation of Matthew Mercer. It now appears in Explorer's Guide to Wildemount, making the spells and classes included there official content.
 * Dunamis appears to heavily rely on a notion not entirely unlike the Many Worlds Interpretation of quantum mechanics - that multiple versions of us exist based on possibilities explored or left to explore across multiple timelines. Each of the members of the Mighty Nein, save Mollymauk Tealeaf, who opted never to use the Beacon, have experienced this sensation in their use of the Fragments of Possibility. However, having much more experience with this magic, the Kryn echo knights and dunamancers seem able to call upon their alternate selves to aid them in battle, in the forms of shadowy echoes.
 * "Dunamis" is the classical pronunciation of the Greek word δύναμις (dynamis), meaning power, especially of divine origins.