Learn a level three ability with Jaster.

Complete Chapter Six.

Complete Chapter Four.

Complete Chapter Three.

Complete Chapter Two.

Defeat a Mimic.

Disarm a trap set on a treasure chest.

This is proof that you've equipped items that activate an Elemental Union bonus skill. Basic skills all correspond to one of five different elements. Equip skills of the same element that line up directly adjacent to each other, and you'll form an Elemental Union based on how many skills are in the line. Check it out on the skill sheet!

Defeat the Ruby Weapon

Defeat the Emerald Weapon

Obtain the Bahamut ZERO Materia

Obtain the Knights of the Round Materia

Raise a Materia to Lv. 5