Busou Renkin

A large, armored figure with a sword stands on a rooftop with two smaller figures, one of whom is a shirtless man with spiky hair and a girl in a school uniform; the scene shifts to a close-up of a hand holding a cracked, hexagonal stone with a symbol, followed by a bright flash and a fight sequence where the armored figure is struck and sent flying backward, landing in a crater on the rooftop.