Obelisk Force

The Obelisk Force (オベリスク・フォース Oberisuku Fōsu) is an elite group of Duelists ranking the highest in Academia in the Yu-Gi-Oh! ARC-V anime. They are loyal to the Professor and carry out his orders without question.

Appearance
All the members of the Obelisk Force wear blue uniforms and helmets that are modeled after "Giant God Soldier of Obelisk". They have crystals on their helmets of the colors red, yellow, and green.

Past
Three years prior to the present storyline, the Obelisk Force helped Reo Akaba capture Serena and Reiji Akaba. They dragged Serena back to Academia and placed an interdimensional teleportation device on Reiji Akaba's wrist to send him back to the Standard Dimension.

Battle Royal
The Obelisk Force were sent by the Professor to aid Sora Shiun'in in bringing Serena back to Academia. They were split into two groups: the first group went with Sora to the Ancient Ruins Area, while the others went to the Volcano Area. While Sora was Duelling Shun, the Obelisk Force Dueled and defeated Ashley, Bram, and Carl. Yūya Sakaki, who had seen them turn the Knight of Duels into Cards, turned berserk and challenged them to a Duel.

They initially seemed at the upper hand against Yūya, but began to panic when Yūya continued to stand up unharmed, despite already receiving much damage from them. They were instantly defeated when Yūya summoned "Odd-Eyes Rebellion Dragon the Supreme King Black Dragon".

The second group who went to the Volcano Area were ready to capture Serena, but Hikage and Tsukikage rescued her and Yuzu while the Youth Team handle them. Three of the six Obelisk Force able to defeat three Youth Team Duelists and proceed with their mission to retrieve Serena while the other three members were Duelling the remaining Youth Team Duelists. They were able to defeat the remaining two Youth Team Duelists with their Antique Gear Hound Dog combo and was about to finish Yū Sakuragi, when Yūgo intervened and took over the Duel, defeating them all at once.

The remaining three Obelisk Force found Yuzu, whom they mistook as Serena and surrounded her. Before they could Duel, Yūri interfered, threatening them to back down or else he will turn them into cards. While Yūri Dueled Yuzu, Dennis led the Obelisk Force to where Serena was. They confronted her, telling her to quietly come back with them, but Serena refused. Along with Shun and Tsukikage, Serena Dueled the Obelisk Force. The Duel was not in Serena's favor since the Obelisk Force already knew her Deck. Before Shun's turn, Michio and Teppei joined the Duel, but they were eventually defeated as well and turned into cards. Watching this, Shingo and Gongenzaka joined the Duel and were eventually able to defeat the Obelisk Force with Shun's "Raid Raptors - Revolution Falcon".

Synchro Dimension Arc
After receiving report from Dennis that Yuzu and Serena were in Synchro Dimension, Reo Akaba ordered Barrett to go to Synchro Dimension and retrieve both of them and the Obelisk Force will also go to aid him once they were done with the preparations. Near the end of the Duel between Crow and Yūya, Sora, Security and Reiji as well as Crow noticed several flying gliders defined to be Obelisk Force.

Serena, still incapacitated from Security's attempt to take her and with Tsukikage and Reira Akaba, was found rather quickly and a flare was lit, slowly drawing the Obelisk Force to her location. Several members then entered duels with Reira, with all of them ending up defeated by the young boy. Others approached the Executive Council's building, which was under siege by Security as well. However, Sergey Volkov intercepted them, defeating several members, much like Reira did. Around the same time, another trio found themselves halted by Tsukikage whom they quickly overpowered with their numbers. They held the upperhand until Sora joined the duel on Tsukikage's side, much to their surprise. This trio was then defeated after Sora, with help from Tsukikage, destroyed their "Hound Dogs" and turned them against their masters. All of the defeated Obelisk Force members were recalled to Academia near-instantly. Reira defeated another group but at this point, he was so tired that he was unable to deal with their continuing reinforcements. He started trembling in fear and recalled his traumatic memories before Yūya arrived to protected him and Serena.

Together, Yūya and Reira defeated another trio before Barrett arrived and Dueled Yūya. While they Dueled each other, the next three members started to go after Reira, who is still recalling his traumatic memories. This trio was then attacked by Sora's monsters and sent back to Academia. Another trio then appeared, led by Yūri. Incapacitating Sora with a "Hound Dog" blocking his Duel Disk, the trio restrained the traitorous Sora while Yūri started a duel with Yūgo, who appeared at the scene, as well.

When Yūri was transported elsewhere by Yuzu's bracelet and Barrett, defeated by the newly arrived Sergey Volkov, took Serena with him at the last moment before retreating to the Fusion Dimension, the remaining three members intended to capture Yuzu, but Tsukikage came, protecting her. The three retreated, seeing no possibilities to fullfil their mission without their commanders Barret and Yūri in the current situation.

Deck
All Obelisk Force members use "Antique Gear" decks. Their strategy relies on using "Antique Gear Hound Dog" to deal effect damage, and Fusion Monsters using "Antique Gear Hound Dog" as a Fusion Material to destroy the opponents field while dealing effect damage when the opponent's monsters are destroyed. They are heavily reliant on Battle Royal rules, as they often defeat their opponents not with power but through sheer numbers with multiple members attacking the same opponent at once.