Brachyura

Order of Ecclesia
Brachyura appears in the Lighthouse as the game's 3rd boss. This fight isn't so much about killing him as it is about getting to the top of the Lighthouse so you can access the elevator to kill him. The Macir glyph works very well in this boss fight. The objective of each part of the fight is to keep attacking him until he turns red. He will then use his giant claw to punch out the ceiling of each section of the Lighthouse. As you get to the top of the lighthouse, you will find an elevator that you can ride down to the bottom to destroy him.