Castle Reuben, known simply as Castle, is a character featured in Tom Clancy's Rainbow Six series. He is a skilled defender, renowned for his expertise in fortifying positions and deploying bulletproof barricades to secure areas against enemy attacks. Castle's unique ability to reinforce entry points makes him a vital member of the Rainbow team, providing strategic advantages in defensive operations. His calm demeanor and tactical acumen have earned him respect among his peers, making him a cornerstone in mission planning and execution within the Rainbow Six universe.