In the manga series Blue Lock, the unique visual metaphors used include the "Locked World" concept, where the characters are metaphorically locked inside a confined space representing their intense competition and pressure to succeed. Another visual metaphor is the "Key Players," symbolizing the pivotal role each player has in unlocking their full potential and standing out among their peers. Additionally, the use of dynamic and exaggerated imagery during intense soccer matches serves as a metaphor for the characters' emotional and mental states during high-stakes games.