Zarm, a spirit of war and conquest that was once the spirit of Earth tempts the planeteers with power and pits them against each other. Matee's "heart" power breaks him free of Zarm's control, allowing him to eventually save the planeteer's from Zarm's corruption. The planeteers realize that an iron fish ethos will do more harm than good, even if done with good intentions and summon Captain Planet to send Zarm back to his world.
Scar is willing to do anything to have power and control. Scar demonstrates that power and control can turn us selfish and impact others negatively. Meanwhile, Simba's motivation for power is fairness and restoring the good.
Terra crashes at the Titan's tower, and she overhears that they think she would be an excellent addition to their team. However, this causes trouble for Terra because she can't control her powers. When sitting outside in the middle of the night, she tells Beast Boy that she isn't able to control her powers. She makes him swear to not tell the other Titans.