Moonglade

Moonglade (魔神月詠斬 (ムーングレード), Mūngurēdo lit. Demon God Moon Song Slash) is a powerful Sword Magic spell; essentially, Moonglade enables the user to catch the enemy's projectile within the cold steel of their blade and absorb it before attacking, which bolsters the power of the strike.

Description
Moonglade is known to be almost insurmountably powerful; in order to harness the spell, the user must be in Overblade Mode; as it's the only source of power that would allow the user to harness the spell to the best of its ability. Once in Overblade Mode, the user grips their blade tightly, gathering and condensing magical energy emitted from their magic origin upon the sword; this causes the sword to glow a light blue. With an enemy's attack heading towards the user, the moment that they raise their blade, the cold steel of the weapon allows the user to absorb the opposing attack through the tip of the blade via the sword's cold steel, converting it into a harmless force via slowing the kinetic energy of the blow and allowing the sword's tip to consume it, focusing it into the tip instantly, bolstering the power of the user's next technique enormously.

That which the user can absorb are nearly any type of magic- excluding Lost Magic, and even some naturally made projectiles; as long as it has kinetic energy, the user can use it to boost their next attack. Once the user's sword has absorbed the attack, the blade glows ever-brighter; which strengthens and accelerates the attack faster than it was originally fired, while adding their own attack into the mixture, making it much more difficult for the opponent to dodge. From there, the user swings the sword forward violently, unleashing a god-speed slash of imaginable power which is able to pierce armour and magical defense as if they were made out of wet paper. A single direct hit is often enough to force opponents to exhaust their own magical energy completely in an attempt to cushion the blow, effectively rendering them drained; however, due to the extreme power of Moonglade, it will more often than not kill any unprepared foe instantly. The motion of the slash causes red rose petals to be released from the sword; these are simply a visual effect; though if Moonglade strikes an object or an unprepared opponent, they will dissolve into rose petals.

Trivia

 * Moonglade (月影, Tsukikage) is a poetic term for the bright reflection of moonlight on water.