Duel Academy (ARC-V)

Duel Academy, referred to as Academia (アカデミア Akademia), is a mysterious school in the Yu-Gi-Oh! ARC-V anime that trains "Duel Soldiers" and is located in the Fusion Dimension, a dimension of unknown origins where Fusion Summon originated. It is run by Reo Akaba under the guise of "The Professor", a man originally from the Standard Dimension, and serves as his base of operations.

This Duel Academy is clearly inspired by the original Duel Academy (named "Duel Academia" in the original Japanese version) from Yu-Gi-Oh! GX (see below); however, it is currently unknown whether they are the same place.

History
Three years in the past, Declan had unknowingly traveled to the Academia via an interdimensional transporter. He eventually met Selena, who he helped escape from faculty members who were pursuing her, only to have them both caught by Reo and several members of Obelisk Force, the elite vanguard squad. Declan was confused by the ensuing discussion about alternate dimensions and the Academia, until the squad hauled Selena off and placed a device on Declan's wrist, which sent him back to Standard.

During his Duel with Shingo Sawatari, Yuto asked about the connection between Leo Duel School and Academia. However, Yuto soon discovered that most of LDS knew nothing.

After Shun Dueled Sora, it is implied that the latter was affiliated with Academia, as Declan mentioned they could learn more about it from Sora. During his Duel against Yuya, Yuto revealed that the Academia attacked the citizens of Heartland and sealed them in cards.

Technology
Their technology is advanced enough to create brain scanners that can access to one's memory. They are also shown to have interdimensional travel technology, as well as abilities to materialize Duels and seal anyone's body and soul into cards.

Allusions to Yu-Gi-Oh! GX

 * Just as the members of Academia use Fusion Monsters, Yu-Gi-Oh GX heavily focused on Fusion Summoning.
 * The members of Academia wear uniforms of the same colors of the dorms from the original Duel Academy: Slifer Red, Ra Yellow and Obelisk Blue.
 * Academia is located on an island just like the original Duel Academy was, and features a castle-esque base resembling the Obelisk Blue dorm.
 * The members of Academia seen invading Heartland City used copies of "Ancient Gear Knight"; the "Ancient Gear" archetype was first used in GX by Vellian Crowler.
 * Academia includes an elite force of Duel Soldiers called the Obelisk Force, all of whom wear blue uniforms and helmets clearly designed after Obelisk the Tormentor and based on Obelisk Blue.