Malleus Key

The Malleus Keys are three magical devices built by the Ruby Vanguard and its allies to achieve the Vanguard's goal of releasing Predathos from Ruidus to allow it to consume the gods of Exandria. The Keys are located in the Feywild, the Shadowfell, and north of Yios, Exandria where the planes overlap a nexus point of the Apogee Solstice in 843 PD. The Key in the Feywild is the oldest, and the Key in Exandria is the newest.

Appearance
The Malleus Keys are large devices, described visually as "extended" versions of the Veilscatter Scope. The Malleus Key in the Feywild is 15 to 20 feet tall and has layers of smooth metal plates and tangled metal cabling. It is powered by numerous arcane cores that are attempting to replace the Moontide Crown as a source of power.

They are located in the Feywild, Shadowfell, and north of Yios, Marquet at the point where these planes overlap with the nexus point for the Apogee Solstice in 843 PD.

Properties
While working on the first key, Ira Wendagoth learned that the initial design of the machine was only able to gather and anchor ley energy, but it was laters improved to accelerate the energy and directly focus it. Ryn, a specialist in the planes who observed the devices at a distance, said the Keys have "some unique planar projector or tether aspect". The Key in the Feywild is known to have kept a ghostly, incorporeal image of Ruidus on the plane, where it does not otherwise appear, and is tethered to this image of Ruidus by a red beam that occasionally bursts with energy. When the Key was destroyed and magical tether was severed, the image of Ruidus immediately vanished from the Feywild.

Ira also told Bells Hells that the Key on the Material Plane emits waves of anti-magic once per minute.

It is not known if the Keys can fulfill their purpose if only two are operational, but right after the destruction of the Key in the Fey Realm, the Key in Marquet was reinforced and enhanced with additional energy sources.

Before Campaign 3
As of 836 PD, seven years before Campaign 3, Ludinus was collaborating with Otohan Thull and the Unseelie Court on the first Key in the Feywild. Ira Wendagoth was contracted as well in the early stages, but was kicked off the project after the first tests were successful. In 836 PD, Birdie and Oleander Calloway stole the Moontide Crown from this device, hoping to delay progress. By this time, Ira had left the project and began working with the Calloways against Ludinus and Otohan as well.

At some point after this, the Vanguard began work on the Key in the Shadowfell. In Unndilar 843 PD, three months before, the Cerberus Assembly (to which Ludinus belonged) forced members of the Grim Verity at the Aydinlan Seminary from their excavating ruins at a site that overlapped with the nexus point so that the Ruby Vanguard may begin building a Malleus Key there.

Campaign 3: Bells Hells
In 843 PD, Bells Hells discovered that Ludinus was working with Otohan Thull and the Unseelie Court on work relating to Ruidus through Ira, who left the Unseelie Court project. They learned more details of the Vanguard's work in Marquet, the Feywild, the Shadowfell through members of the Grim Verity and resolved to sabotage at least one of the devices. After they captured a member of the Ruby Vanguard, the group learned the names of the devices, Malleus Keys, and that the Key on the Material Plane was "near completion" and most guarded. By this time, tensions had arisen between the Assembly and the Unseelie Court; Bells Hells sought to take advantage of this to sabotage the Key there.

On advice from Morrigan, Bells Hells followed Ruidus and the red tether connected to it to the Shiver Keep. They successfully entered the courtyard, and Laudna noticed that it had been modified to use arcane power sources rather than the Moontide Crown as originally intended. Laudna and Orym climbed inside the machine to determine how best to sabotage it, ultimately deciding to plant dynamite on the inside and to attack the arcane power sources on the outside. Imogen's Witch Bolt, Laudna's Eldritch Blast, and Fearne's Wall of Fire caused the machine to explode before the dynamite detonated, destroying the Key and severing the tether keeping the image of Ruidus in the Feywild.

When they returned to the Material Plane, Bells Hells found that the key at the Tishtan excavation site had been reinforced in response to their destruction of the Feywild key.

When Bells Hells encountered Beauregard Lionett and Caleb Widogast near the key on the Material Plane, Beau and Caleb told them that they, along with members of Grim Verity, had gone to the Shadowfell to destroy the Malleus Key there. They damaged it, but not beyond repair, and much of their team did not survive. Beau and Caleb then infiltrated the Tishtan site with Planerider Ryn, and remained hidden after Ryn was petrified.

Trivia

 * Malleus is Latin for "hammer".
 * The Malleus Keys have a similar name to the Factorum Malleus, an Aeorian project aiming to kill the gods.