The Gaia Armor is an boss from Grandia. It is encountered inside Gaia, the final dungeon of the game. The Gaia Armor appears in two parts, but it's HP depletes as one. The Gaia Armor has the ability to cast Dead Circle, Killer Tackle, Healer and Gravity.
The Gaia Armor has two parts, the Body and Eye. The Body will cast Dead Circle and Killer Tackle both of which can cause nasty damage. The boss is surprisingly agile, so moving around the arena won't save you. Instead, take the fast route and throw everything at him and cast some defensive spells if you have the time.