An evil galactic armada has come to destroy the planet Earth and the newest team of Power Rangers must harness powers from Rangers of the past to stop them as the Power Rangers Megaforce.

When the evil Warstar aliens attack Earth, the supernatural guardian Gosei and his faithful robot assistant Tensou recruit five teenagers with attitude to combat the invading forces. Equipped with powers that grant them mastery over martial arts and other forms of combat, the teenagers transform into the latest champions of good: The Power Rangers Megaforce!—Elliott Monroe

When the Warstar Alien Armada plans to destroy Earth, an entity, by the name of Gosei, recruits a group of teenagers to become the Power Rangers Megaforce and eventually evolve into Super Megaforce. However, they need more power than they think to stop this armada. To achieve this, Gosei grants them the ability to use the powers of legendary Power Rangers, rangers from the past, and later unite with the actual Legendary Rangers for a huge, epic battle the Rangers have never encountered before.