Enter Merla: Queen of Darkness Voltron: Defender of the Universe : Season 2 Episode 12

Zarkon enlists the aide of Stride, a legendary Tiger fighter, in his battle against Voltron. Stride wants no part of Zarkon's personal grudges, so Zarkon falsely claims that Planet Arus has challenged Stride's honor. As Stride leaves to fight Voltron, Zarkon welcomes a new ally, Queen Merla. After hearing of Zarkon's plan, Merla decides to head to the battle sight, because she doesn't want Zarkon getting all the credit. Stride meets Keith in a one-on-one fight. Keith earns Stride's respect by fighting valiantly, which leads to Merla attacking both of them.