Yu-Gi-Oh! VRAINS/Fridge

Fridge Brilliance

 * During the Knights of Hanoi attack on the Cyberse, they imprisoned all of the AIs except for Ignis. Each of the AIs has a distinct look and color, red, yellow, orange, blue, green, and purple (Ignis). At first this seems to be an easy way to tell them apart... until you remember that Monsters in the Duel Monsters game (with the exception of the Egyptian God Cards) are one of six attributes, with each attribute associated with a color: DARK (purple), EARTH (orange), FIRE (red), LIGHT (yellow), WATER (blue), and WIND (green). Ignis' comment on how the other AIs don't like him suddenly makes a little more sense.
 * Duels during data storms being restricted to Speed Duels could be because the systems can't handle Master Duels when it's currently being flooded with an influx of data, making Speed Duels all the system can handle.
 * After an entire season of "but you'll still take battle damage" in Arc-V, one might think it odd that the Knight of Hanoi brought up the fact that Cracking Dragon cannot be destroyed by battle just before he was about to lose, as that effect will not change the outcome of the duel. A major purpose of Cracking Dragon however is its use as a weapon of terror outside of duels, as it deletes anything it comes into contact with. By destroying it by battle, Yusaku has put it out of commission, if only temporarily.
 * Yusaku's Duel Disk uses physical cards unlike the latest duel Disks, which use digital cards. If Yusaku were to ever have his account deleted, he wouldn't actually lose any of his cards since they're physical objects rather than digital objects. Just one more benefit of using outdated tech for a hacker like Yusaku.

Fridge Horror

 * When Ignis disconnected the Cyberse from the rest of the network, what happened to the other AIs that were trapped?
 * Yusaku no longer enjoys dueling and mostly uses it as a weapon to fight the Knights of Hanoi. He's exactly the kind of person who needs the help of the previous protagonist, Yuya, the most and yet, will never meet him outside of non-canon specials.