Complex sentence: The third member of Mach Storm, Sigma is older than RD, is rather cocky and argumentative, and tends to look down on RD. Despite this, he is a capable pilot.
Split into simpler sentences: The third member of Mach Storm, Sigma is older than RD and tends to look down on him. He is rather cocky and argumentative, and tends to look down on RD. Despite this, he is a capable pilot.