It's well known that Tiamat is also a Demonic Dragon, so it was understandable that Jiang You kept mistaking her effects for Yubel's.
Tiamat declared, "I activate my own effect! Upon my successful Special Summon, I can Set one Spell/Trap Card that lists 'Tiamat' in its text directly from my Deck to my field! I choose [Anti-Genesis]!"
The Authority of Anti-Genesis manifested around Tiamat.
"This card cannot be destroyed by card effects. While this card is face-up on the field, the effects of all Servants are negated, except for [Beast] and [Master] Class Servants. Additionally, this card can bypass my own immunity to other card effects—though I no longer have that effect... Anyway, it increases the Attack and Defense of all 'Tiamat' Servants on the field by 2000!"
[Tiamat (Primordial Spirit Origin)] Attack Power 6000 → 8000!
With a staggering 8000 Attack Power, she could now be affected by other card effects, making her less of an absolute threat than before. However, her ability to return from the Graveyard or Banished Zone after leaving the field was still a major headache. The only ways to deal with that would be to banish her face-down or return her to the Deck or hand.
Furthermore, [Anti-Genesis]'s Skill Drain-like effect was a powerful lockdown. It was a good thing King Hassan's on-summon immunity wasn't part of his card text.
Regardless, this version of Tiamat was less of a threat. Leaving her on the field was actually the better option. If she left the field and summoned the previous Tiamat, Jiang You's targeting effects would be sealed again.
"Then I'll activate [Encyclopedia of Knowledge] once more! I Tribute Host Hundred Faces to destroy that Set Card in your Backrow!"
Since Hundred Faces couldn't activate her effects anyway, Jiang You might as well use her for one last purpose. This would also reduce the number of Servants on the field, preventing Tiamat from recovering too much Life Points and complicating the final blow.
"Counter Trap Card [Eye of the Dark Star]! When a Spell/Trap Card is activated, I can activate this card to negate its activation and destroy it! If successful, I can then destroy all face-up Spell and Trap Cards on my opponent's field!"
Tiamat thwarted Jiang You's attempt to destroy her Backrow and, in the process, wiped out his Field Spell Card as well. Jiang You's Graveyard lock was broken.
"Blown away again."
Tiamat's destructive power was undeniable, and it was on full display in this Duel.
Jiang You glanced at the only monster left on his field—the vanilla [Hundred Faces]—then at his hand. If he could just survive this turn, he could use Fate's Draw to add [Surrender Thy Head] to his hand. By sending three more Hassans to the Graveyard, he could search for [Archivist of Hidden Knowledge]. Then, he'd use the Archivist's effect to return King Hassan to his Deck and add [To Sound the Funeral Bell] to his hand, allowing him to summon King Hassan once more.
Finally, he would use Old Man of the Mountain's attack-banishing effect to banish [Tiamat (Primordial Spirit Origin)], dealing 8000 direct damage and securing an easy victory.
"I Set one card in my Backrow and end my turn!"
Jiang You now had two cards left in his hand: [Morning Glory] and [Archivist of Hidden Knowledge]. At the start of her next turn, Tiamat would have one card in hand, one Set Card, a face-up [Anti-Genesis], and [Tiamat (Primordial Spirit Origin)].
"Your gaze lingered on the Graveyard for quite a while. You're planning to rely on Old Man of the Mountain to win, aren't you?"
Jiang You was stunned that Tiamat had read his intentions from a single glance. He quickly averted his eyes. "Hey, no mind-reading!"
"Understanding a child's thoughts is one of a mother's essential duties, you know."
A gentle expression appeared on Tiamat's draconic face. "In that case, Mother will stop you. My turn, I draw."
"Old Man of the Mountain truly poses a threat to Mother. Therefore... Summoning is forbidden!"
Like a certain fake rabbit, Tiamat activated a card clearly designed to counter him.
"I activate the Trap Card [Authority of the Beast II]! Until the start of my next turn, no Servants other than Beast Rank Servants can be Special Summoned!"
"You can do that?"
Because the effect applied directly to Jiang You, even King Hassan's immunity to card effects during his summoning turn couldn't bypass this lockdown.
"A child cannot defy their mother. The moment you called me 'Mother,' the outcome was sealed!" Tiamat declared confidently. "Now, let's do this again! I activate the Quick-Play Spell Card [Genesis of the Eleven Beasts]! From my Deck, I Special Summon [Mušhuššu], [Umu Dabrūtu], [Mušmaḫḫū], and [Ušumgallu]!"
This time, Jiang You had no way to deal with them all at once. The four Magical Beasts were successfully summoned to the field.
[Mušhuššu] Beast / Level 8 / ATK 3000 All Servants on the field cannot be in Defense Position. Battle damage inflicted by this card is doubled.
[Umu Dabrūtu] Beast / Level 8 / ATK 3000 Cannot be destroyed by card effects. When your opponent activates an effect that targets a card, you can change the target to this card.
[Mušmaḫḫū] Beast / Level 8 / ATK 3000 Unaffected by Trap Cards. When your opponent activates a Trap Card, you can Tribute this card to negate that card's activation and destroy it.
[Ušumgallu] Beast / Level 8 / ATK 3000 Can attack three times per Battle Phase. If this card destroys a Servant by battle, you can draw 1 card. Cannot be destroyed by battle. When this card is targeted for an attack, the attacking Servant's ATK is halved.
The four children of Tiamat gathered around her, letting out threatening howls at Jiang You. Their intelligence was low; they acted mostly on instinct.
On Jiang You's field, his only Servant, Hundred Faces, was forcibly switched to Attack Position.
[Hundred Faces] DEF 0 → ATK 0.
"Good children."
Tiamat launched her final assault against Jiang You. "Entering the Battle Phase! Attacking Hundred Faces! It's over, Jiang You! I, your Mother, have won this battle!"
Quetzalcoatl's expression shifted drastically. If Jiang You lost, the next round would be physical attacks.
Jiang You raised a hand to stop Quetzalcoatl, who was poised to strike. He then seized the opportunity to strike back at Tiamat while she was vulnerable. "Not yet. I must thank you for banishing my brothers, who possess both destruction and banishment effects, earlier. Otherwise, I wouldn't have survived this turn."
By referring to the Eleven Beasts as his "brothers," Jiang You was deliberately trying to establish a closer connection with Tiamat.
"I activate the Quick-Play Spell Card Proof of Existence! This card allows me to target a 2-Star or lower Assassin on the field. That card cannot be destroyed by battle until the end of this turn, and any battle damage it takes is reduced to 0! The target I choose is Hundred Faces!"