The Magna Defender goads Leo to destroy him, saying it's the only way to bring Mike back, and even offers to fight him to make it self-defense. Leo refuses, saying the Magna Defender isn't evil and that this isn't the way to bring Mike back.
The Magna Defender when saving Terra Venture by himself.
Incorruptible Pure Pureness: According to the Magna Defender, Mike's conscience weighs heavily on him and is effectively tearing him apart.
Jumping Off the Slippery Slope: In order to exact revenge against Scorpius, the Magna Defender is willing to allow Terra Venture to be destroyed.
The Reveal: The battle in which Zika died occurred on Mirinoi. 3,000 years later, Magna Defender saved Mike from falling to his death and used him as a host to escape the pit.
Redemption Equals Death: Magna Defender atones for his actions by saving Terra Venture and not letting the Rangers or Torozord help.
Shadow Archetype: Seeing the Rangers risking everything to save the colony, Magna Defender observes they're what he used to be before Zika died and thus is this trope to them.