Are we supposed to sympathize with Paradox or not? While his goal seems noble, since he comes from a future ruined beyond recognition and he intends to save the world from destruction, he does rather monstrous things in order to achieve that goal, including heavily damaging Judai and killing a lot of innocents, as well as Pegasus and Sugoroku.
Are we sure that the protagonists do the right thing? Does killing a person who intends to avert an utterly ruined future solve everything? Do people truly have the power to change the future?
Ass Pull: The three protagonist draw the perfect cards in their first turn to win the duel. The worst example is that the three last cards they played are obviously designed for the final turn. Yugi and Judai have two Trap Cards with similar names and basically the same effect just to buff Yusei's Stardust Dragon. And Yusei's Trap Card Stardust Mirage allows him to revive all of their monsters that are destroyed during the turn, but it requires Stardust Dragon on the field. However, Stardust Dragon was stolen at the beginning of the movie. There is no way that Yusei could predict to get his card back. Also, it only works because of violation of the rulesnote Yusei activated Stardust Dragon's effect. It should be revived on Paradox' field, but it doesn't and it shouldn't even be able to be revived in the first place, since it wasn't Synchro Summoned.
On a Chinese forum Paradox is often referred to as BOSS. Among the Japanese he is called Para-san or Paradox-san/-sama. Other people are starting to refer to him as Squidhead.
Material, including the movie itself, tying the three series together are referred to as Yu-Gi-Oh! 5DX.
Harsher in Hindsight: The film is pretty hard to watch after Yu-Gi-Oh! ARC-V featured interdimensional wars being waged with Duel Monsters, destroying or corrupting entire worlds.
Hilarious in Hindsight: Kazuki Takahashi stated that Pegasus' least favorite food is squid. In the movie, someone with hair resembling a squid is out to kill him. Least favorite food, indeed.
Ho Yay: Johan isn't even present and only mentioned once, but the producers still somehow manage to make the impression that there is something between Judai and him. Judai is practically furious when Paradox plays Rainbow Dragon, while he made no such outburst when Paradox played Sho's Cyber End Dragon the turn before.
When Judai and Yusei drives to the past to take Yugi, this is how they sit.◊ Yeah, Judai puts his hands on Yusei's hips rather intimately there. In fact, thanks to this movie, the Starshipping ship (Judai/Yusei) has been launched and is still very well-liked even now.
Memetic Molester: After witnessing Judai sitting behind Yusei on his motorbike and Yusei and Judai talking about how they are similar to each other, Japan made Judai launch even more ships. Paradox is also a popular target for Judai.
With Paradox's hair resembling a squid, the fandom is joking around with "an epic battle between marine invertebrates" - starfish for Yugi, jellyfish for Judai and crab for Yusei.
People enjoy making Paradox say "YA-HA!" in fan material thanks to him and Hiruma sharing voice actors.
Yusei's distorted face (which can be seen well during a freeze frame) as he is knocked back by Paradox's attacks gained a slight popularity in fanart.
Nightmare Fuel: Paradox's fusion with Sin Truth Dragon. He is clearly in pain when he pays his Life Point cost for the monster's summoning (explaining that he sacrifices his body in doing so), his eyes temporarily go blank during the fusion, and the next thing we see is a close-up of Paradox's veiny, angry face. He also makes Dark Marik-esque faces at the protagonists afterwards.
So Bad, It's Good: For some people, the epic cheesiness of the dub saves it from being a bad film.
Woolseyism: Yugi and Yami's brief dialogue before their transformation. The original has Yami suggesting that he take over, with Yugi simply agreeing. The dub instead has Yugi stating that they'll rise to the challenge, implying that they'll be working as a team rather than him just letting the Pharaoh do all the work. We then get to see the full transformation sequence, complete with a revamped main theme and iconic cry of "YU-GI-OH!" with Yugi's voice fading into Yami's, the latter of which isn't present in the original.
◊ Yeah, Judai puts his hands on Yusei's hips rather intimately there. In fact, thanks to this movie, the Starshipping ship (Judai/Yusei) has been launched and is still very well-liked even now.
