In the first generation anime of Yu-Gi-Oh, the Red-Eyed Black Dragon is Jonouchi’s ace, and the Demon Summoner is an excellent monster in the game deck. The fusion of the two, [Dark Demon Dragon], is a testimony of the friendship between Yugi and Jonouchi. It was also the beginning of the friendship between the Red-Eyed Black Dragon and the Demon Summoner. Because of this fate in the original work, K Club was always able to include Demon Summoning when it released the Red Eye series of cards.

[Demon Summoning] First of all, the demon summoning looks like this. In the first generation, there was no need for sacrifices to summon higher-level monsters, so the star rating of this card was not taken seriously by everyone, but later it became the reason why it had to be hidden by the anime team. Because after the "Duel City" chapter, summoning higher-level monsters begins to require sacrifices. Monsters with 5 to 6 stars require 1 sacrifice, and monsters with 7 to 12 stars require 2 sacrifices. The 6-star Demon Summon has an attack power of 2,500 points, while the game's ace Black Magician has a 7-star level, but the attack power is the same as the Demon Summon, not to mention the True Red-Eyes Black Dragon, which only has an attack power of 2,400 points. Therefore, after the "Duel City" chapter, it is almost impossible to see the game using Demon to summon this monster.

[Red-Eyes Fierce Thunder King-Evil Demon] When K Club enhanced the Red Eyes series, they summoned the devil and put it on a red-eyes vest, thus giving birth to the Red-Eyes Fierce Thunder Emperor. The original demon summoning was originally a demon that used thunder and lightning to attack, and the unique attack skill was called: Demon Falling Thunder. The card image of this card enlarges the elements of thunder and lightning, and then adds red eyes as a symbol of the Red Eye series. The demon summoning power after turning into Red Eyes is also stronger than the original version, and has a powerful effect that can destroy all monsters on the opponent's field whose defense is lower than the attack power of this card.

[Demon Dragon Dark Demon Dragon] The original Dark Demon Dragon is the fusion of the True Red Eyes Black Dragon and Demon Summoning. From the card drawing, this Demon Dragon should be the product of the fusion of the True Red Eyes Black Dragon and the Fierce Thunder King. The upper half of the background of the card is a true red flame, and the lower half is a white electric current. The first thing that comes to mind for the demonic monster that wields thunder and lightning is the summoning of demons. However, compared to the handsome Dark Demon Dragon in the original version, this Demon Dragon looks like a fool because of its stupid face. From the True Red-Eyes Fierce Thunder Emperor to this Demonic Dragon, the Demonic Summoning is like rebirth with the True Red-Eyes Black Dragon.

[True Red-Eyes Undead Dragon] This true red-eyed undead dragon is the source of the immortality of the true red-eyed black dragon. To this day, we still don’t know why the red-eyed black dragon took the form of this red-eyed undead dragon. There is no other card in the card pool that touches on this background. What's weird is that this card bears the name and image of Red Eyes, but its effect has nothing to do with Red Eyes Black Dragon. It's really confusing.

[Immortal Demon King Skeleton Demon] Since the red-eyed black dragon is no longer dead, naturally the demon summons as a good friend cannot lag behind. Different from the strange undead transformation of the True Red-Eyed Black Dragon, the undead transformation of the Demon Summons can be determined to be accompanied by synchronization, so the culprit is naturally the zombie carrier, which is a typical undead tuned monster. This can be confirmed by the fact that the conditions for this card's Synchro Summoning specify Zombie Carrier as a synchro material.

[Zombie Carrier] This thing is not only harmful to demon summons, but also many monsters in the elf world have turned into undead monsters because of being infected by it. He is the culprit who caused the large-scale undead events in the elf world. However, we may be able to work backwards, that is, the Demonic Summoning was first infected by the zombie carrier, and then the undead Demonic Summoning infected his good friend, the Red-Eyed Black Dragon. This can also explain why the original immortality of the Red-Eyed Black Dragon was not accompanied by synchronization.