Complex sentence: He was first discovered by the Turtles in his cell, then he, Spyroach, a Parasitic Wasp and a Squirrelanoid discovered that Metalhead opened their cells.
Split into simpler sentences: He was first discovered by the Turtles in his cell. Then he, Spyroach, a Parasitic Wasp and a Squirrelanoid discovered that Metalhead opened their cells.