• Yuri was the only one of Zarc’s reincarnations not to duel against Sawatari Shingo.
• Yuri was also the only one of his counterparts not to be in any sort of relationship with Serena (the Fusion dimension’s incarnation of Ray)
• Yuya, Yuto, Yugo and Yuri’s clothing and colour schemes are based on the card background of their dimension.
• In the Japanese dub, Yuya and Yuri share a voice actor while as Yugo and Yuto’s voice actors are twin brothers. This is similar to how their characters look the same and were originally one person. Yuzu and Serena also share a voice actor like Yuya and Yuri do. Interestingly, Yugo, Yuto, Ruri and Rin’s voice actors, all immediately retired after ARC V finished in much the same way as their characters were ‘killed off’ in the earlier stages of their appearances, Yuto, Rin and Ruri in particular.
• The second ending in ARC V (Future Fighters) is sung by Yuya/Yuri and Reiji’s voice actors. One of the singers for the second ending (One Step) is also the same voice actor who voices Ruri Kurosaki later in the show.
• 2 characters from GX (Edo and Asuka), 9 from 5D’s (including Jack and Crow, Yeager and many other minor characters) and 3 from ZEXAL (most noticeably Kaito, with two minor characters) have cameos in ARC V. No characters from Duel Monsters were added, however, Reiji Akaba shows many similarities to Seto Kaiba.
• Yuya is the only Yu-Gi-Oh protagonist to date, to lose in the last 60 episodes of their show, suffering defeat against Sergey in the Synchro Dimension arc.
• Yuya, Yuto, Yugo and Yuri are all the same height, factoring in height of face/chin level and hair ’extensions’ to character design.
• If you take a letter from each of Yuya, Yuto, Yugo and Yuri’s names (In that specific order and take 1st letter of Yuya, 2nd letter of Yuto, 3rd letter Yugo, 4th letter Yuri) The word formed is Yugi, Japanese for game and the name of the first series protagonist.
• LITERALLY EVERY SINGLE DRAGON IN ARC V is animated AT LEAST ONCE in CGI
• Yugo rides a TK2000PS model D-Wheel
• Yugo’s use of luck and dice rolls on some of his cards is like Jounouchi from DM, and several of his monsters bring Rua’s Morphonic monsters to mind, such as Speedroid OMK Gum, which even transforms like one. His interactions with Rin even can remind viewers of how Rua annoyed Ruka, albeit Rin and Yugo are love Interests and not siblings. 
• Yugo’s deck is one to Yusei’s, being comprised mostly by Machine-Type monsters and having a WIND Synchro Dragon as its ace, but also a little with Jack’s using the same Power Deck tactics. His Hi-Speedroid Puzzle also seems to be a nod to Speed Warrior.
• Yuri is meant to be Yuya’s opposite in every way: Yuya’s kind, understanding and wants to make a person smile; Yuri’s cruel, impatient and loves filling someone with terror. 
• In contrast to the other dragon boys, who can routinely win without needing their dragons, Yuri’s strategy is pretty much “Fusion Summon my Dimension Dragon as quick as I can, then wreak havoc with it because it’s so good I don’t need anything else.”
• In all Yu-Gi-Oh ‘VS’ screens and duels (aside a few in GX) the ‘hero’ or ‘person you are going to root for’ is ALWAYS placed on the right hand side of the screen. The ‘villain’ on the left. However, in the second episode of ARC V in the first and only duel with Yuya against Yuzu. Yuzu is seen on the right hand side. Yuya on the left. This is most likely a direct reference to how Yuzu’s previous incarnation Ray, defeated Zarc, Yuya’s previous incarnation and saved the world, thus becoming a hero. While it is a small easter egg, it is a direct reference to how, while Yuya seems to be a hero, he is also the main antagonist of the series. The FORESHADOWING!!!

ARC-V 2018 Anniversary, Day 14: Hunting  魂を悪魔に売った決闘者 ー The Duelist Who Sold His Soul to the Devil