Voltron: Defender of the Universe: The Complete Series
Voltron: Lion Force, A Ghost and Four Keys
S1 E3:
Keith, Lance, Sven, Hunk and Pidge ask for help from the Princess Allura to find Voltron. With guidance from the ghost of her father, King Alfor, they find four of the five keys needed to form Voltron. With no choice, they head into battle with only their robot lions to keep back Doom's soldiers.