Zeldon's Research Facility

Zeldon's Research Facility is an isolated tower situated in the far north of Britannia. Fraudrin as Dreyfus assigned it to be the base of the Pleiades of the Azure Sky.

History
This tower was built on the side of fossil trees on the direct orders of King Bartra, probably to prevent against possible invasions by Northern Barbarians. After being named Great Holy Knights, Dreyfus and Hendrickson, manipulated by Fraudrin, exiled Denzel Liones and his followers there so that they do not oppose their coup against the Royal Family. However, much like Hendrickson conducting experiments to free the Demons from the Coffin of Eternal Darkness, Denzel conducted his own, more "ethical" research to counter them.

Great Fight Festival arc
After being captured by the Pleiades, Fraudrin finds himself chained, while Denzel begins his "interrogation" by thrusting a sword "blessed by years of Druid prayers" into his right shoulder. Despite the pain, Fraudrin manages to free himself, but this does not prevent Denzel from wanting to prove that a Human like him can kill a Demon as one of the Ten Commandments, and that even Dreyfus would be happy to make this sacrifice to to redeem from his faults towards the Kingdom of Liones.

While Fraudrin is stuck with Denzel, Waillo, Deldry and Arden stand guard with an Absolute Cancel Incantation Orb which Arden nearly knocks down while playing with it. Luckily, Waillo picks her up just in time and hands her over to Deldry "against the promise to marry her". Inside Fraudrin fights with Denzel, but when he wants to unleash Rakan, his attack finds himself delayed by Deathpierce's Melody. This is where Fraudrin realizes he is trapped with Denzel and Deathpierce in a Perfect Cube.

When Arden suggests that Waillo and Deldry go to Vaizel to participate in the Great Fight Festival, Grayroad, transformed into Dogedo, comes to see them pretending to want to take over the guard, and recovers the Incantation Orb which she uses immediately to break the Perfect Cube.

Fraudrin reveals that he is only an "honorary" member of the Commandments, assigned to replace the real Commandment: no other than Gowther of the Seven Deadly Sins..

On the way to Vaizel, Waillo, Deldry, and Arden are shocked to spot the real Dogedo and immediately decide to turn around to go help Denzel and Deathpierce. With Grayroad's arrival, Fraudrin says he is ready to resume the fight against Denzel and Deathpierce, but unwilling to risk falling victim to a Commandment effects, Denzel agrees to let both Commandments go, despite protests of Deathpierce. As Fraudrin and Grayroad leave, they run into the other Pleiades, and Fraudrin takes the opportunity to stab Deldry, now that her power no longer works on him.

Before leaving, Fraudrin chooses to kill the Pleiades by pulverizing Zeldon, but they are all saved just in time by Dogedo's power.