Aquastrike

Aquastrike, also known as Water Sword, Enwater, and Liquid Steel, is a recurring ability in the Final Fantasy series. It is always a water-elemental attack to one target, and is mainly attributed with the ability Spellblade.

Final Fantasy IX
Water Sword can be used by Steiner when he is paired with Vivi in a party.

Final Fantasy X-2
Liquid Steel, learned by Warriors, is a water-elemental attack to one target. It requires 20 AP to learn and 4 MP to cast.

Final Fantasy XI
Enwater is learned by Red Mages, which adds Water-elemental damage to their physical attacks.

Final Fantasy XIII
Aquastrike is a Ravager ability, learned by only Lightning, Snow and Fang.