From Dragon Quest Wiki

Gigasmash is a a lightning-charged skill that serves as the greatsword counterpart to Gigaslash.


Dragon Quest XI: Echoes of an Elusive Age[edit]

The Luminary learns gigasmash after spending 25 skill points to unlock the ability in his character builder board. It costs 16 MP to perform, and will deal up to 250~280 damage to a group of enemies. The motion of the skill is similar to Unbridled Blade, but slightly more angled instead of a direct overhead slash.