S1·E44 Voltron vs. Voltron

A remote planet named Yadil has thrown off the bounds of Zarkon's oppression. They decide to join the Alliance, and invite Voltron to a celebration in honor of this great event. However, Voltron shows up strangely early, and with him a strike force of Doom Soldiers. They take over Yadil and set a trap for when Keith and the rest of the team arrive with the real Voltron.