The ages in this one will be a bit different. This is going by the notion that the invansion of Heartland/XYZ dimension happened four years before the events of Arc-V, meaning that they had one year of peace before the attack. That's how I'm explaining Rio's age here.

Characters/Ages: Yuya (14), Rio (19) and, briefly mentioned, Hiragi-san (Zuzu's father - 35) and Zuzu (14)

Darkness

"Yuya... what are you doing?" somewhere next to her, Hiragi-san said. She turned to look at him for a moment and saw a serious expression on his face before she turned to look back at the dueling field.

The duel between Yuya and Isao-kun had been brutal, even in terms of what she had seen, but Rio could have never predicated the turn of events. She had stood up worriedly when Yuya appeared to have a seizure but sat down again when he looked calm right after. That wasn't the case, however, as she realized that his eyes - usually calm and friendly - were now a stormy, blood-red, as though he had been possessed.

"Swing, Pendulum, swing harder!" Rio watched as Yuya began to chant. "Build an arc across the ether, Pendulum Summon! Come forth, my monster servants!"

"Servants?" she repeated, stunned. The tomato-head she knew would never call his beloved monsters 'servants' or anything akin to it, which only reinforced her theory of possession. But by whom? All Isao had done was jab at him (physically and emotionally) yet nothing that would cause such a sudden transformation."

"Level 4 Lacoodown and Silver Claw, overlay!" he shouted. Rio stood up again, stunned as she knew that Yuya shouldn't be able to XYZ summon (or know how) as he had never asked her for any tips when it came to it. So who taught him? Did he learn on his own for the moment? "Fangs of the deepest darkness, rise up against this foolish oppresion! Descend now! XYZ Summon! Appear now! Rank 4! Dark Rebellion XYZ Dragon!"

The reporter of the duels went wild, spluttering about 'Pendulum, into XYZ!? What is it!?' as Zuzu somewhere to her father's right gasped out an almost silent 'Yuya!' yet all Rio herself could do was stare as Yuya detached both overlay units to lower Idaten's attack and then declared the attack.

"Idaten's effect!" the clearly desperate Isao began to explain how a certain level of monster couldn't attack his Idaten and Rio pitied him. XYZ monsters didn't have levels after all. She watched in silent horror as Yuya nearly repeated her exact thoughts and she had to look away as the attack lowered Isao's LP from 4000 to 0 in one strike and a visually brutal fashion that reminded her too strongly of her actions during the Numbers War nearly five years ago.

Rio bit her lower lip and could only watch as Yuya was declared the winner and stunned audience began to whisper and worry about what happened. Yuya himself, who seemed to have returned back to normal, wondered what was going on and he looked so broken that she wanted to jump over the area they were seated and run over to him to give him a hug.

But she knew that wouldn't help. Yuya had discovered a very dark part of his soul, which seemingly had no problems with being brutal against Yuya's opponents. Whatever it would prove to be dangerous for them too, she couldn't know.

She didn't want to imagine it at all.

I hope that I didn't copy too much of the episode since, clearly, Rio hadn't been there so... yeah.

Thanks for reading! :)