Byleth knew there was something wrong with his student. He had seen her get frustrated when called a child, her getting frightened at the mention of ghosts, and her throwing a tantrum when she got particularly impatient. What he had never seen though was the pure rage and bloodlust she had exhibited once she had caught sight of that mage.
She was normally intelligent and reliable in battle, so to see her lose control of herself like that and break formation was a shocking sight. It was fortunate that he had been able to intervene toward the end. Lysithea had clearly exhausted her spell reserves yet she still seemed to ready to continue casting magic. Even at the cost of her own vitality.
Byleth wasn't a fool, he knew that there was something wrong with her body, but he didn't have to worry about her breaking herself until now. Before he could talk with her, to confront her over her reckless behavior, he heard the familiar sound of a horse in the distance and turned to find the Death Knight charging at them.
He was the first to move by pushing Lysithea out of the way and matching the Death Knight's scythe with his new sword. Byleth let out a grunt as he struggled to keep his blade up.
Be careful. This one is different from the rest! Sothis's voice called out in his head.
I know!
The Death Knight was strong. The only one that could compare was his own father and he had yet to beat Jeralt in a true fight.
His opponent pushed him back and swung again from across his steed. This blow sent Byleth into an unbalanced state and then the third swing would knock his sword out of his hand.
Before Byleth could react, The Death Knight swung downwards and impaled him in the stomach.
"No!" Lysithea screamed in despair as he was cut down before her. The rest of his students and even Claude looked at him in shock as the scythe was impaled in his chest.
Byleth took one last look at the face of his student stained with desperate tears and then his would-be killer before reversing the flow of time. He was brought back to the beginning of the fight, just as the Knight had begun to charge.
It was fortunate that he hadn't had a need to use the Divine Pulse in this mission until now. He would need every single one he had if he was going to survive long enough for the rest of his students to reinforce him.
You have three pulses left. Do not let them go to waste!
Byleth pushed Lysithea out of the way and matched the Death Knight's scythe once more. They repeated the same movements up until the Death Knight tried to push him back. With knowledge of the previous engagement in mind, Byleth was able to subtly step out of the way and duck underneath the second swing. He then swung his blade, scoring a strike against his foe's right leg. The sword he now wielded shredded through the armor and was able to cut into the Knight's flesh. It was only a light wound, but Byleth had been able to shed some blood.
The Death Knight continued to stare at him, as if they hardly noticed the damage he had just done. "Not bad you are different from the rest."
Byleth stayed silence as he took up a stance once more. His eyes hardened as he tossed away all emotion and all thoughts of everything else except his opponent in front of him. He could no longer afford to fight as the Professor. The Ashen Demon had come, and all the Demon cared about was victory. The only way this was to be achieved, was to kill his opponent in front of him.
The Death Knight switched the hand that held its weapon. It had clearly noticed the change in front of him.
"I do not sense any hatred or fear in you. Do you believe that being void of emotion gives you strength?"
The Ashen Demon charged, pivoted on his foot, and swung at his opponent's chest. The Death Knight would block the blow with the shaft of his weapon.
"You do not enjoy the thrill of battle. So, what motivates you?"
They continued to trade blows, the Demon doing his best to parry, dodge, and redirect as necessary. A reckless offensive against the Knight would likely lead to his death, he needed to stall and see if there were any openings to exploit.
"Why does the Demon fight? Why does it choose to exist with such weakness?"
The Demon rolled under a swing only to be struck down by a Thoron as he tried to get up.
The flow of time reversed.
The Demon repeated the motions, rolled again, and this time used his blade to deflect the spell.
Two
The Knight knew magic. He couldn't afford to give it any distance. He had to continue mounting pressure even as the knight threatened him with the mobility of its steed.
The demon closed in, attempting to use the long reach of his opponent's weapon against. By constantly staying close and forcing the Death Knight to block with its shaft he was able prevent a counterattack.
The Death Knight swung its fist out only for the Demon to dodge it. With a feint, the demon would bait the next swing, step back to avoid it, and thrust his sword. This time he cut the forearm of the knight's dominant arm. Unfortunately, it wasn't enough to be a debilitating injury.
"What will it take for you to toss away the rest of your humanity?"
This… thing is quite insane.
The Ashen Demon wouldn't even answer the voice in his head as he took a low stance with his blade.
But then again, you're quite strange in the head too.
"You have been putting much effort into protecting these children," the Death Knight turned toward Lysithea who had been watching the battle between the two of them. The girl's eyes went wide as the Knight's attention shifted on her. "Perhaps they are what shackle you."
The Knight turned his steed and charged at Lysithea.
"No!" the Professor shouted as the Demon was pushed aside. Byleth tried to chase after Death Knight but simply couldn't keep up with its steed. He could only watch as his white-haired student took out her blade in desperation and tried to block the blow. With a single swing she was sent flying through the air and fell roughly onto the ground.
Byleth was helpless to watch as the Knight then trampled her with his horse. A crack could be heard as Lysthea's skull was crushed under the horse's hooves. Blood, bone, and brain splattered onto the floor of the Monastery.
He could hear Hilda screaming at the sight and Marianne sobbing as she prayed. He could see the rest of the Golden Deer with looks of fear and pain etched in their faces as they saw one of their meet a gruesome end. Even Lindhart had collapsed to his knees, his face pale as he looked at the remains of Lysithea.
Leonie and Lorenz shouted in rage and charged at the Death Knight with their weapons. Likely to their deaths.
The flow of time reversed.
One
Byleth couldn't stand to see the sight again. He threw his sword in desperation while the Knight's back was turned on him. It embedded itself in the knight's shoulder, driving deep into its left arm, but that wasn't enough to stop its charge. The Death Knight swung at Lysithea.
Lysithea was able to block the weakened strike with her sword and jump out of the way as the horse galloped past her. As she picked herself up her and Byleth's eyes met.
The Knight dropped his scythe and began casting a Thoron.
Byleth shouted.
Lysithea was too late to react as the spell struck her back and pierced through her chest. The life left her eyes and her body fell to the ground with a smoking hole in its chest.
The Golden Deer reacted much the same as they did before. Ignatz looked broken, Raphael shouted for his lil sis, and Claude had completely lost his composure. He snarled and ran forward to aim his bow at the Death Knight.
The flow of time reversed.
And then there were none.
My power is spent. This is your last chance!
Not again. He refused to let it happen again.
His sword took on a brilliant orange light, his unknown Crest manifested itself, and thrusted the sword forward. The sword cracked, it split, and to flew through the air elongating itself like a whip. It wrapped itself around the back leg of the Death Knight's horse. He pulled, ripping off the horse's leg and sending both it and its rider crashing to the ground.
The sword retracted and returned to its original form as Byleth charged. He was short on breath, his crest and the Relic he held had taken much more out of him than he had expected, but he refused to stop running. Not until he had ensured the safety of his student.
The Death Knight stood up once more though it was clear that the wounds it had received had finally begun to take its toll. "What strength… I didn't expect to encounter someone like you… How fortunate," it said before it promptly disappeared in a flash of light.
Even as the Death Knight disappeared Byleth continued running. He didn't even register his student calling for him until he kneeled down and put his hands-on top of her shoulders.
Lysithea could hardly let out a word as her Professor suddenly kneeled down and grabbed her by the shoulders. It was the first time she had ever seen him get so physical. Even around Jeralt the most he would do was nod or give him a handshake.
"Are you alright?" Byleth asked as he looked her in the eyes. His face was as monotone as ever but there was a notable strain in his voice. It was hard for Lysithea's face to not to go red though with how close he was to her.
"I'm okay Professor," she replied hesitantly. The Death Knight hadn't even gotten that close to her before the Professor toppled him. What would've caused such a drastic change in his behavior then?
"No injuries?"
"Nothing Professor I can assure you."
The Professor looked at her carefully before letting go and standing up. "Good."
"That was a bit scary back there wasn't it Teach?" Claude called out as he and the rest of the Golden Deer finally joined the two of them. "We should be thankful that they left you a Heroes Relic to use."
"Even with heroes relic you were able to take down such a dangerous enemy, as expected of Captain Jeralt's son," Leonie commented.
"It isn't because they share blood that the Professor is so strong," Lysithea said. "But rather work and dedication he put into his training."
"Father is the one who had trained me and taught me most of what I know, but I also had to work hard for it. You are both correct to a certain extent."
"I'm glad we had you with us Professor. I shudder to think of what that Knight would've done to a vulnerable maiden like me," Hilda said as she shuddered.
"If anything, Lysithea was the closest to becoming a victim," Ignatz commented.
"Though that was mostly her own fault," Lindhart commented as he turned toward her. "What was that Lysithea? You broke formation, risking yourself and the rest of us. Not only that but once you reached the mage all you had to do was distract him long enough for the Professor or one of us to come assist. You wouldn't have been so helpless if you hadn't all your magic on that one person."
Lysithea flinched. What Lindhart had said hurt, but it was true. In her fit of rage she had used up all her magic and became a burden that the Professor had to risk his life to protect. It wasn't just Lindhart either, the rest of her class were looking at her suspiciously over her actions.
"He's right you know," Claude commented. "Not very smart of you to charge without the rest of us. Even if you stopped him from escaping."
"For once I agree with Claude. That was reckless and unbefitting actions for one of the nobility," Lorenz said.
"Lysithea you were acting pretty wild back there," Hilda admitted.
"It was certainly unplanned, but it worked out in the end didn't it?" Ignatz argued. For some reason having Ignatz defend her only made her feel worse.
"I don't know. I'd rather us all be safe than risk getting hurt over a fancy sword," Raphael argued. "No offence there, Professor."
"None taken. My student's safety should take priority after all. I understand that there are risks to be taken on the battlefield but that is no excuse to break formation."
All Lysithea could do was stare at the stone floors of the Mausoleum. The guilt she carried in her gut just seemed to get heavier at each of her classmates' words.
"Perhaps we should all return to the monastery?" Marianne suggested. "We're all tired and perhaps a bit shaken by what happened."
The class glanced among themselves before eventually agreeing.
"Marianne's right." Claude said while glancing at Lysithea. "We can have this discussion once everyone's healed up and rested."
With that, they made their way out of the Mausoleum.