Chimeric Fortress Dragon, at first glance it doesn't seem particularly powerful, yet it unexpectedly caused a significant upheaval in the environment upon its release.
The main reason, though, is because of Cyber Dragon.
In some ways, the birth of this card was both a blessing and a curse for Cyber Dragon, the strongest offensive force recognized in the environment at the time.
Looking on the bright side, it means Cyber Dragon became the nemesis of all Mechanical Race monsters. No matter what kind of powerful Mechanical Race monster the opponent summons, you just need to Special Summon Cyber Dragon, and then Cyber Dragon can devour all Mechanical Race monsters on the opponent's field in one go, transforming into Chimeric Fortress Dragon.
It's equivalent to Cyber Dragon having an inherent "Super Fusion"-like ability to clear the field. Even if you have five "immune to all effects" indestructible monsters on the field, in the face of Cyber Dragon, they're just premium fodder.
But from a pessimistic perspective, it also means Cyber Dragon itself became fodder for the opponent.
Before this card was born, it was common for one side to jump out Cyber Dragon, and rely on a single Cyber Dragon to crush the entire Duel. An Attack Power of 2100 was an insurmountable barrier for lower-level attackers, and the suppressive power of a Cyber Dragon used to be very strong.
But after this card's release, the situation changed. The opponent just needs to casually summon a Mechanical Race monster to devour your Cyber Dragon... no, even the controller must remember not to summon a second Mechanical Race monster while Cyber Dragon is on the field, or else it will surely be exploited by the opponent.
Furthermore, you can't hold onto the hope that "maybe the opponent doesn't have Fortress Dragon." Because, unlike now, the first time Yu-Gi-Oh! rules introduced the restriction of "no more than fifteen cards" in the extra deck was in 2008, which is when the Synchro Era officially began.
The reason is said to be due to the official distribution of card sleeves to tournament participants back then, leading many people to bring a 99+ Super PLUS version of the extra deck to exploit the card sleeves. K Society thought this would lead to a bald fleece, so they limited the number of extra cards to prohibit the behavior...
Incidentally, actually in the GX era, there was no explicit rule that the main deck had to be below sixty cards, only requiring that it be above forty. The sixty-card maximum rule was also added during the 2008 "Master Rule" when Synchro Summoning was first implemented.
Meanwhile, the side deck regulations were also adjusted. Previously, Yu-Gi-Oh! side decks required exactly fifteen cards, neither more nor less. After Master Rule implementation, it changed to "under fifteen cards."
That was likely the first large-scale wave of quitting Yu-Gi-Oh! Not only because of the new summoning method "Synchro Summoning," but also due to many old players finding the addition of upper limits to the main deck and extra deck rules inexplicable, as it once allowed the theoretical play of excessively large decks for entertainment. The new rules put an end to that.
In short, before the Synchro Era came, the extra deck had no upper limit. So virtually one hundred percent of players would carry "Chimeric Fortress Dragon" in their extra deck, meaning any time you dared to use Cyber Dragon, you had to be mentally prepared to have it devoured.
Of course, this phenomenon with physical cards was based on the premise that Cyber Dragon was a top-tier versatile offensive tool used by almost everyone.
But the animated world is different. Here, not everyone has a Cyber Dragon, so the appearance of the "Chimeric Fortress Dragon" seems to upset only one person.
That is Marufuji Ryo, whose facial muscles are twitching faintly at the moment...
"The original attack power of Chimeric Fortress Dragon becomes the number of monsters used as its Fusion Material times 1000 points." Yugen smiled, "Since it's Fusion Summoned using two Cyber Dragons, the attack power becomes 2000."
[Chimeric Fortress Dragon, Attack Power 0 → Attack Power 2000]
Marufuji Ryo: "..."
Finally, Caesar began to seriously ponder a question—
—Is there really any need to show respect when the opponent is a dog?
This was the toughest Duel he had ever faced, and it was the first time his long-standing beliefs felt shaken.
At that moment, his repressed instinct and desire for victory reached its peak.
He must win, he cannot lose.
All the bonds with old friends, all the respect for the opponent's victory — these don't matter anymore.
It's fine to lose to anyone, just not to this kind of person.
A shadow was quietly spreading in Caesar's heart...
"Attack." Yugen said, "'Chimeric Fortress Dragon', direct attack on Marufuji!"
[Chimeric Fortress Dragon, Attack Power 2000]
[Marufuji Ryo, LP 1600]
Marufuji Ryo gritted his teeth.
Am I really going to lose here, lose at the hands of my old friend?
No, that absolutely cannot happen.
He doesn't want to lose. Not today, not now, not in this way, he cannot lose to this opponent.
"Continuous Trap 'Minimization'!" Marufuji Ryo shouted, "Choose a monster on the field with original attack power over 1000, that monster's level decreases by 1 star, attack power decreases by 1000!"
Yugen nodded: "The effect of 'Chimeric Fortress Dragon' is its 'original attack power' becomes the amount of material times 1000 points."
"That's right, so the effect of Minimization can apply!" Marufuji Ryo said, "Decrease 'Chimeric Fortress Dragon' by 1000 points attack power!"
The massive Fortress Dragon visibly shrunk by half in size, and even the energy blast it emitted seemed weakened.
Boom!
Marufuji Ryo was bombarded head-on, staggered back two steps, half kneeling on the ground, surrounded by black smoke.
[Marufuji Ryo, LP 1600 → LP 600]
"Caesar's Life Points are just a flutter in the wind!"
The host finally snapped out of the "Cyber Dragon's sudden betrayal" shock, continuing his commentary duties.
"This... this... the tactics of Master of the Yellow Robe are incredibly despicable... oh no, I mean ingenious." He continued to explain, "Caesar's powerful formation was so casually broken by him.
With this, Card Cannon Attacker hasn't even attacked yet, if the attack goes through, Caesar still loses..."
He couldn't help but sound a bit regretful.
He truly thought Caesar tried his best. But alas, Caesar is strong, but ultimately, he's only the king among students.
The King cannot defeat someone who's not playing fair.
"Card Cannon Attacker, direct attack." Yugen said.
A three-shot fire, like the judgment of the God of Death. The firelight illuminated Marufuji Ryo's somewhat disheveled face in the projection effect, the academy king's initial fighting spirit gone, eyes only reflecting a kind of heart-tired fatigue...
He even surprisingly realized that at that moment, he had the thought: should I just give it to him?
This match, let him have it, I don't want to continue fighting.
But as soon as he realized this absurd thought, he promptly extinguished it.
No, that's not acceptable.
He is a Duelist, a Duelist who must put forth his utmost effort, sparing no cost in pursuit of victory at all times.
Only by fighting with all his strength, seeking victory by any means, can he show the utmost respect to his opponent.
Even if for this... he has to let go of his old friend.
"Activate Cover Card!"
Facing the flames, Marufuji Ryo stood, the fierce flame in his eyes reignited.
"Trap Card - Wall of Power!!!"
Yugen chuckled with great interest: "Oh, you actually used this move."
"Can be activated when the opponent's monster's attack would make you take battle damage." Caesar shouted, "Until battle damage becomes 0, for every 100 damage, send one card from the top of the card deck to the graveyard!" (Original effect)
The physical card version modified it to 500 damage.
Marufuji Ryo shouted hoarsely, pulling out a handful of cards from his card deck, fluttering down like snowflakes in mid-air.
"From my card deck... I send nineteen cards to the grave!"