The Servant nodded. There were no more words exchanged as he closed his eyes for but an instant before gazing upwards, resolve of steel gathered. His grip on his weapon's handle tightened, then slackened slightly and he reared back, as though to swing.
Such thing was foolishness, of course. Siegfried was not so mighty that a mere swing would send a current of razor wind towards the demon, nor would Balmung enlarge like a certain staff in order to reach the opponent that high up. Besides, he had already acknowledged that a normal swing wounding it was an impossibility at most.
But that was fine. After all, Noble Phantasms were meant to achieve something that should have been an impossibility, the true trump card that propelled Servants above their station.
Wisps of energy akin in color to a waning sun emerged from the pommel of the greatsword, more specifically, the jewel embedded on it. This was something unknown to this world, which had left that part of its history behind — the Fifth True Element, Ether from the Age of Gods. It wrapped around the blade, coalesced as though an espectral sword that sought to overlap with the one Siegfried held.
This was the weapon that had once bathed the world in twilight, the sword that had struck down the Evil Dragon, Fafnir, in a time long past. His muscles tensed as coiled springs, ready to release, and he spoke the words
Phantasmal Greatsword - Felling of the Sky Demon!
Twilight expanded as he swung, a crescent of raw, undiluted power with the sole purpose of destruction. This was the second Noble Phantasm the Dragon-Blooded Knight possessed, a weapon able to rend armies with little difficulty. The beam was directed upwards, seeking to engulf its master’s enemy, to leave behind not even ash.
In these circumstances, the Demon’s position was indeed a fortuitous one — were he to have unleashed it in any other direction but upward, while it might not called as much attention, there was little doubt the land would have been razed beyond repair. As it was, it would miss the buildings and simply vanish into the night sky.