Complex sentence: He sports an X-shaped scar on his right cheek, which was originally supposed to be used to get Kurita arrested, and the only one of the three to figure out that Sena was actually Eyeshield 21.
Split into simpler sentences: He sports an X-shaped scar on his right cheek, which was originally supposed to be used to get Kurita arrested. He is also the only one of the three to figure out that Sena was actually Eyeshield 21.