Outside the airship's window, an enormous spike pierced the clouds.
It was a tower, a pitch-black monolith that thrust straight into the sky, like a weapon an ancient giant had left behind in the mortal world.
Its summit vanished into the clouds, with no end in sight. Only its suffocatingly vast outline remained, casting an imposing shadow over the city below in the sunlight.
"Wow-it's so tall!"
Gon practically pressed his face against the glass, his breath fogging a small patch of the window as his eyes shone with a child's purest wonder.
"Tch. It's nothing special."
Killua kept both hands in his pockets, playing the worldly, unflappable boy, but the slight lift at the corners of his mouth betrayed the stir of emotion inside him.
He had been here before.
Yet every time he saw this building again, it still left him awestruck.
Lin Yan stood quietly before the window. Deep within his eyes, a barely perceptible glimmer slowly swirled.
"Qi Observation Technique."
In an instant, the world in his eyes shed its physical colors.
The black tower became an immense "furnace" in his vision.
Countless streams of energy, varying in color and thickness, converged from every direction and were drawn into the tower.
Some were crimson, representing vigorous vitality; others were golden yellow, representing pure fighting spirit; still others were grayish black, representing cold murderous intent...
Desire, excitement, blood vitality, obsession, and the purest life energy of all-Nen.
The auras of thousands upon thousands of fighters intertwined, collided, and burned within the tower day after day, finally rising into a vast "blaze of energy" steeped in iron and blood. It surged skyward, even churning the clouds.
This was no sacred ground for fighters. It was an enormous "alchemy furnace," using people as fuel and combat as its flames