It was certainly the biggest battle that had ever occurred in that world. From behind came the intermittent release of Flame Breath, guardian knights were burned to death and continued to fall one by one. The warhead formation used by the Sylphs cut down the flocking giants with their powerful swords, drilling a vast hole into the wall of meat.
At the tip of the warhead was the little black Spriggan. His equipment grade was way weaker than the Sylph warriors, but with his sword moving beyond god-like speed, anything that his sword touched was instantly cut and blown apart.
Lyfa flew through a gap that the Sylph warriors opened, immediately reaching behind Kirito. After blocking the sword of a guardian knight that was going to attack Kirito's back Lyfa buried her katana in its mirror mask. Holding her katana while turning, the neck of the knight flew away from its body, and the body burned with a white flame. Kirito turned to Lyfa, and said while moving only his lips.
"Sugu, I leave my back to you."
"Count on me!!"
She met his eyes and responded wordlessly, then put her back against his back. The two of them turned round and round, cutting down the guardian knights that continuously appeared in front of them.
One-on-one, the giant knights shouldn't be that easy for her to kill. However, as she stuck to his back and matched his speed, Lyfa felt as though the knights became slower and slower. No— Maybe her nervous system accelerated? It had happened in kendo matches before, Lyfa was enveloped by the sense that she could grasp everything going on around her.
It felt as though she and Kirito had become one being. With their nervous system directly connected, the pale electronic pulses flowing from one to the other. Without looking, she knew how Kirito was moving behind her. While his sword cut into a guardian knight's neck, while turning, Lyfa struck high into the same knight's neck and finished it off. On another knight's mask that Lyfa damaged, Kirito struck the same place Lyfa had just hit, cutting deeply.
Kirito, Lyfa, the Sylph warriors, and the dragoon brigade moved like a single white-hot entity, continuing to touch and melt the wall of guardian knights with no limit, going deeper and deeper. The number of knights was unlimited, but the amount of space in the dome was fixed. As long as they continued to progress, the moment would come sometime.
With her spirited shout Lyfa cut a guardian knight in half, it collapsed and disappeared.
Beyond the last few knights, even if only for an instant, she saw the zenith of the dome.
With a shout, Kirito moved from behind Lyfa as a black flash of light rushed toward the gap in the wall of flesh. The last group of guardian knights approached him from all directions while raising a cry of resentment to prevent intrusion. They numbered nearly thirty.
Lyfa instinctively swung her katana and threw it at Kirito's left hand with all her might.
The green blade spun through the air and settled into his hand as though it was sucked there.
With a shout that shook the entire dome, Kirito held the greatsword in his right hand and the katana in his left. They shot out with fearsome speed in a dual attack.
Cutting down from the upper right. Cutting up from the lower left. Two shining swords changed angles slightly and drew a snow-white circle that looked just like the corona of a solar eclipse. The bodies of knights that got caught in his ultra-speed slashing were cut to pieces like paper, spreading out into the surroundings.
This time it was clearly visible beyond the End Frame of the ring of white flame. Entangled like a mesh of tree branches at the center of the canopy of the dome, was a circular gate divided into pieces by a cross. Spanning the trunks of the World Tree, the final gate leading to ALfheim, the castle up at the top of the tree.
The small figure in black continued to fly toward the gate, pulling a tail of light behind him. He arrived. At last.
In front of Lyfa's eyes, the bodies of the guardian knights were quickly and repeatedly piled up and filled any open space in an instant. Sakuya, who noticed that Kirito broke through the defensive line, shouted from the rear:
"Everyone fall back, retreat!"
Evading together with the Sylph team while diving with the support of Fire Breath attacks, Lyfa, for a moment, looked back in the direction of the canopy. She was unable to see Kirito's figure due to the wall of guardians, but reflected in the eye of Lyfa's heart, rose the figure aiming for the place that no one had ever reached, rising higher and higher.
Fly— Go— Go anywhere! Through the giant tree, soar through the sky, to the heart of the world—!