Complex sentence: In the episode "Power Surge" Terrosaur found a large quantity of energon, and used it to augment his power and finally defeat Megatron, but Megatron was rebuilt by Scorponok, and Terrorsaur's reign was short-lived.
Split into simpler sentences: In the episode "Power Surge" Terrosaur found a large quantity of energon, and used it to augment his power and finally defeat Megatron. But Megatron was rebuilt by Scorponok, and Terrorsaur's reign was short-lived.