Aquamarine

A young man with spiky hair and a school uniform stands with arms outstretched, surrounded by swirling blue energy that erupts from his body, then he is shown from behind holding a glowing blue sword vertically, followed by a bright flash, a close-up of his determined face with blue energy swirling around his eyes, and finally a man in a long coat with a confident expression, surrounded by blue energy, as the sequence loops. The setting is a dark, indoor environment, likely a room or hallway, with the primary action being the characters' use of blue energy-based powers.