Complex sentence: Leatherhead has also made an appearance as a boss in', although the cutscene shows him as an ally, although we see the cave-in caused by Stockman that causes Leatherhead to be buried beneath what remains of the Turtles' old lair.
Split into simpler sentences: Leatherhead has also made an appearance as a boss in', although the cutscene shows him as an ally. We see the cave-in caused by Stockman that causes Leatherhead to be buried beneath what remains of the Turtles' old lair.