Character Arc
Simon begins as a meek, insecure orphan who hides behind his adoptive brother Kamina and feels most at home digging tunnels for his underground village. His discovery of the drill-shaped Core Drill and the tiny mecha Lagann sets him on a path he never sought, and for much of the early story he relies on Kamina's confidence to push him forward rather than trusting his own strength.
The loss of Kamina shatters Simon and nearly breaks him, sending him into a deep depression before he resolves to honor his brother's dream by becoming a leader in his own right. He grows into the commander of Team Dai-Gurren, piloting Gurren Lagann through the war against the Spiral King and shouldering responsibility for the lives of his comrades and the future of the surface world.
By the final arc, Simon has matured into a hardened and selfless hero who leads humanity against the cosmic Anti-Spiral threat. Wielding the immense Super Tengen Toppa Gurren Lagann, he embodies the series theme of relentless willpower, ultimately choosing a quiet, humble life after saving the universe rather than clinging to power or glory.