When they reached the training grounds, they found Jeritza setting up. Mercedes gave him a strange look. "You remind me of someone."
"I have never seen you before," Jeritza tried to convince her.
"I'm sorry. You just look a lot like my brother, Emile von Bartels," Mercedes said.
"...That is not my name," Jeritza tried to say.
"There's no need for lies anymore," Edelgard told him. "Mercedes, this is your brother."
"Lady Edelgard..." Jeritza tried tried to protest.
"Take off that mask, Emile," Mercedes implored him. "Let me see your face."
Jeritza hesitated, but complied. "You should stay away from me, Mercedes. I don't want to hurt you, but I can't always control my urge to kill."
"I doubt you could harm her even if you wanted to now," Edelgard told him. "Our time in Hyrule made us all much stronger than we were."
"Perhaps you should spend some time catching up with your brother," Rhea suggested to Mercedes.
"I think I will," Mercedes agreed. She took Jeritza's hand, and the two of them left the training grounds.
After the two of them had left, Rhea took two training weapons: a training sword and a training axe. Both were weighted to match the weight and balance of a real weapon; as the saying went, "Practice as you plan to fight."
"Show me what you have learned, Cyril," Rhea offered.
"All right," Cyril agreed.
With that, he lunged forward with his axe, and Rhea found herself on the defensive. Cyril was fast, much faster than Rhea had expected. And his blows had a lot of strength behind them, far more than she would have expected.
However, even if she wasn't quite in her prime anymore, she was still secretly Saint Seiros, the War Saint who had slain the evil king Nemesis. Cyril was strong, and his technique was excellent, but there was a moment where he left himself open. She just needed to-
Her attempt at stabbing him with the practice sword was prevented by what felt like a barrier between her practice sword and Cyril. Cyril noticed what she was doing, and jumped back out of the way before she could pierce the barrier.
However, this allowed Rhea to take the initiative for herself, and she started attacking Cyril with quick sword strikes. Yet even though he only parried most of them, it felt like none of them were getting through.
Rhea came to a conclusion. Whatever Cyril was doing that kept her from hitting him, he was using magic to accomplish it. A hint of pride in her adoptive son swelled within her, but so did a sense of jealousy over the fact that she hadn't been the one to teach him magic.
(It wouldn't occur to her until later that this was one of the first times she had consciously thought of Cyril as her son.)
Cyril backed away from her, stopping at two meters. Rhea could have pressed her advantage, but she wanted to see what Cyril would do.
Once he stopped, though, he disappeared from view completely.
Where had he gone? Had he warped somewhere? No, there had been no flash of light.
Rhea's battle instinct went off, and she dodged a blow she couldn't see coming. In return, she threw a punch where her instinct told her her opponent was, even though she couldn't see him.
Even though she had held back, her punch sent Cyril, made visible again, flying. Yet he got up as if he hadn't been hit at all.
Rhea attacked again with her practice sword. And yet, there was so much resistance to her strike that the sword burst into flame—along with her forearm.
The blow was slowed and weakened to the point that Cyril blocked it easily. He then started attacking with blows that had much more force behind them than Cyril should have been able to deal.
It suddenly became clear to Rhea what Cyril was doing. He had somehow weaponized the air itself, and was using air pressure to block her blows and strengthen his. His invisibility trick had been caused by him using the water vapor in the air to bend light around him.
It was a clever move, but Rhea was the Sky Dragon. The air wouldn't stop her. She just needed to use the right amount of force at the right time.
When Cyril tried attacking her next, she pushed his axe aside with her sword and threw a punch into Cyril's solar plexus. The air resistance set her fist on fire, but she didn't let that stop her from delivering the punch. It hit with the force of a punch by a strong human, and Cyril fell to his knees.
Rhea helped him up. "Very good, Cyril. I doubt anyone in Fódlan outside this room could have beaten you."
"Thanks," Cyril said weakly.
"Your use of the air was quite brilliant," Rhea praised. "I wish I could have taught you myself, but I am proud of you."
Cyril beamed.
Byleth took two practice swords and offered one to Link. "Let's go one round."
"Are you sure?" Link asked. Byleth nodded.
The two of them watched each other like hawks for the first sign of movement. It was Link who broke the standoff, slashing at Byleth from the side. Byleth expertly parried his blow, and then retaliated.
The two of them moved quickly, faster than most of the eyes on them could follow. Any blow that one tried to land was deflected by the other. Link seemed to have the advantage, as he was able to put Byleth on the defensive more often, but it wasn't a telling advantage, and Byleth weathered the storm quite well.
The moment Link had seemingly been waiting for came when Byleth tried swinging at Link. Link dodged perfectly, and time seemed to warp as Link launched a flurry of attacks faster than the eye could follow.
And when the flurry of attacks ended, everyone could see that not a single one had landed. Somehow Byleth had avoided or parried them all.
Byleth then put Link on the defensive with abnormally fast attacks of her own. Link wasn't done, though, and his guard remained perfect, no matter what Byleth tried.
Finally, Byleth drew back and swung at Link with one powerful strike. Link met the strike with one of his own. It seemed strength would decide the match, not skill.
But the wooden swords simply couldn't take the strain, and Byleth's sword broke.
"I think that's a victory for Link," Jeralt said.
Link shook Byleth's hand. "Good match. It could have gone the other way."
"You fought well," Byleth praised Link. "I'd like to try again sometime. Perhaps with stronger practice swords."
"You taught your daughter well," Rhea said to Jeralt.
"Honestly, some of what she comes up with, I don't even know how she does," Jeralt admitted.
Rhea silently agreed. Jeralt couldn't have taught Byleth to avoid Link's subtle time-warping. This as good as confirmed her suspicions. Byleth had at least some of the power of Sothis. Perhaps the connection went deeper.
Hopefully when she explained everything, Jeralt would understand and would let Rhea ask Byleth questions about her connection to Sothis. For now, though, there were other matters to discuss.
"I believe there was mention of a wraith that attacked you and your companions, Flayn?" Rhea asked.
"Yes. He was called Wizzro, and he had apparently served Ganon before," Flayn confirmed. "We met him on the way to Riola Spring..."