Diabolico was the main villain in Lightspeed Rescue in the beginning, but when Impus became Olympius, that changed the game. They were rivals and then trouble ensued by the force of the power rangers and they were both defeated, time and time again.
Then Diabolico helped the team seal Queen Bansheera. He was cast into hell and never returned. Diabolico and Olympius clashed, yes, but battle over the star power made things competitive.
It was intense, but I think at the end of the day, Olympius was more powerful, but Diabolico was more steadfast. Olympius was greedy and power-hungry.
