List of Sentai's Dark Lords

Well just take a wild guess why this is the entry. :-P Bwahahahaha!

Emperor Ragorn- He is the emperor of the 100 Bouma Tribe. It's kind of ironic that Riki Honoo/Red Turbo was able to defeat him in a one-on-one duel. He was killed twice.

Dai Satan/Lokar- It's not surprising he's named Dai Satan, after all he rules the Netherworld. He's the ultimate evil in Zyuranger with whom Bandora sealed a deal with. Like Ragorn, he was defeated twice. However he only appeared in episodes 30-31, 47-50. He was first defeated in episode 31 by Kyokyoku Daiyzujin. In episode 50, his physical form was destroyed. Only if he could just get rid of Hercule in Dragon Ball Z for using his name in vain. LOL.

Daimaou/Master Vile- His name literally means Great Demon King. Funny he shares the same name with the antagonist in Akazukin Cha Cha.

N-Ma- He was the ruler of Infershia. Although he was initially fragmented, he however managed to assemble himself back together. In the end, it took the power of the Ozu family to finally destroy his physical form. Whether or not he'll return is up to fan's imagination.

Long- I think he qualifies in the list. He's actually a dark lord himself. In reality, he is a force of malevolence with five heads working as one mind. He's really despicable as he enjoys inflicting human suffering. His immortality is impressive as he couldn't be killed. He was sealed off into a ball twice- one in the Gekiranger finale and two, in the Go-onger vs. Gekiranger special.

Doukoku- I think he qualifies too. Apparently he can be equal to Yakumo in Yuu Yuu Hakusho.