Luffy's Hard Trial! The Power of the Snake Sisters' Willpower!

When Luffy beats Bacura, the panther executioner, Luffy goes to fight Boa Marigold and Boa Sandersonia. Boa Sandersonia plays the statue of Margueritte to cause Luffy pain. Luffy then unleashes a very rare and strong haki which surprises everyone and the haki Hancock also has.