Voir Voltron: Defender of the Universe - Lion Force - Episode 56

The capital city of Arus has finally been rebuilt, just in time for Zarkon to send an army of Crab Robeasts to level it. Keith and the others can't fight with all the citizens caught up in the destruction. Then the Robeasts dig into the castle, carving up the foundations. It is up to Princess Allura to travel deep inside the castle and uncover King Alfor's secret energy weapon to power up Voltron and destroy the Robeasts!