Excalibur

After Yosel had bought the blade for Arthur, he snapped his fingers together once again before taking them back to an island in the sky, however it was not the same one as the one that Arthur had destroyed. The one that Arthur broke into half was warmer much like a summer field however this one was similar to a cold winter with snow covering the entire area and a small cottage in the middle of it which Yosel was going to be staying inside.

"So I guess we're going back to training?" Arthur asked to which Yosel gave a nod.

"I would like for you to work on your own speed however we're not going to be using the treadmill this time, instead, I want you to run around the entire island until you feel like you're going to die. Go at your maximum speed and remember, there's no reason for you to stop since Lucifer will always keep you alive so feel free to break past your limits as many times as you want," said Yosel before teleporting inside the cottage and leaving Arthur to go on the edge of the island so that he could run around it as many times as possible while staying consistent by going as fast as he possibly could.

"What should I do with this?" Arthur asked himself as he considered placing it in his storage spell where he kept many of his things however he wanted to mess around with his blade a bit while he was running so instead of leaving it to the side, he began to go swing it around while running. This way, he would get used to using his blade all while increasing how fast he could move as well which also in turn increased his stamina which placed a large role in how many spells he could make use of.

After running for 30 straight minutes, Arthur began to feel tired as he wanted to stop and take a break as he could feel his face get red and have his entire body exhausted as he gasped for air. Even so, he knew first hand that Lucifer was forced to keep him alive which caused him to keep running. The only thing which made Arthur happy while he was struggling to run was the blade in his hand which he kept swinging around. However at some point, Arthur got tired of doing that and simply ran while holding on to his blade.

At some point though, Arthur began to get sleepy, that didn't mean he was going to stop running, instead, he would run while he slept like he did when he was on the treadmill. The only problem was that he needed his body to make the turns that he did so that he wouldn't fall of the edge of the island. This wasn't a problem when he was on the treadmill because he just needed to run in a straight line which this time was a problem as he needed to turn all the time. Even so, Arthur was too tired to come up with a plan and as such, he allowed him to close his eyes and placed full trust in his body.

While sleeping, Arthur began to converse with Lucifer who was waiting to speak to him.

"You have a keen eye for dangerous objects," said Lucifer which Arthur looked at him with a confused expression.

"What are you talking about?" Arthur asked as he didn't know what Lucifer meant by his words.

"Do you know the name of the blade that you're carrying around you like it's a toy?" Lucifer asked to which Arthur shook his head as he didn't know.

"Wait, do swords even have names?" Arthur asked to which Lucifer began to believe that his host as an idiot.

"Only the greatest blades in all of history are given names. One of those being the blade you're carrying. The person who sold it to you probably though it was a fake since it only activates when one that it befitting of the blade holds it. As such, you should be wary of it," said Lucifer.

"Why? It seemed like a regular blade to me," Arthur replied casually.

"The name of that blade is Excalibur, truly a legendary blade that would cause a war for its possession. The only reason it hasn't caused that war is because it is believed to be nothing but a myth. It has been forgotten by many and those who still know about it's legacy see it as nothing but a dream. Your luck is truly terrifying. Not only do you posses the king of the underworld but the most powerful blade in all of sorcery history. If you wanted, you could take over the world right now. Although it would be quite difficult since you don't have a good grasp on how to use any of your greatest powers to thier full capacity," said Lucifer.

"What do you mean by that? The blade is mine so it should work right?" Arthur asked to which Lucifer began to laugh.

"The Excalibur in your hand is not the real form of the blade. Do you believe that such a legendary blade would have such a boring form? The real Excalibur is a majestic beauty capable of erasing a whole country with a single slash. It might even be much more powerful than that," Lucifer explained.

"So how do I exactly make it activate?" Arthur asked to which Lucifer began to get serious.

"You see, the problem with the blade is that you don't pick it, it picks you. If you're not worthy of it, it will not show you it's true form. More over, I believe that it has already picked you. After all, it's been lost for thousands of years and it finally made its appearance to you, there's no mistaking it, it will activate for you," said Lucifer which brought a smile on Arthur's face.

In the outside world, the blade in Arthur's hand split in to two while still attached by the hilt as a blue light came from the middle which allowed extreme heat to flow out of it.

Excalibur had been activated.