Quake2 is the second level spell on the Earth Magic Materia, with a base spell power equal to 1.5x the base magic damage. It takes 6,000 AP to learn and 28 MP to cast. The enemy Bagrisk and the bosses Ultimate Weapon and Lost Number use the spell against the player. Ultimate Weapon only uses the spell on land battles as well as in Mideel, and Lost Number only uses the spell in its Magic form.
Quakra is a moderate level Black Magic spell available for purchase in Guera for 1,500 gil. The spell costs 3 AP to cast and has a spell power of 13. The spell can only be used if the Quakra Tome item is in the player's inventory.
A variation called Strong Quakra can be used when two Psyched Up characters cast Quakra during the same turn.