Arthur began gathering the energy in the atmosphere, constructing the widely-known object named a "sword."
It was a greatsword, to be precise.
Arthur's eyes glowed a deeper hue, while his hands brushed along the vibrant particles of energy. With his palms in the air, gripping the ethereal hilt of the rather massive, vibrantly-colored greatsword sword that pointed towards the sky, Arthur began leaking a destructive aura into his surroundings.
To quel the rage of the "Oblivion Torrent," as described by Lucien, Arthur planned on simply splitting the condensed energy in half.
It was a rather bold tactic, but one glance at the phenomenon told Arthur it was not possible to use conventional means. Lucien's spell was a spell, unlike any other spell Arthur had ever seen in his life.
Because it didn't use mana as its source.