[POWER RANGERS] Who's the most ruthless and powerful villain

All the Villains are always evil in all the season and theyall want to rule the world,destroy it. But all villains were not ruthless and powerful. See all of them were evil but few were powerful and ruthless. A villain whom we felt that yes he could defeat us. A villain who made us shout at him that why are you ruthlessly hitting our rangers. A villain who was too powerful for rangers to combat in final climax. You can't put mesagog,lothor or emperor grumm in that category. For me my ruthless and powerful villain was Ransik of time force. In the climax had he not surrendered after striking his daughter down,He would have destroyed our rangers. I almost thought that rangers are going to be finished.And throughtout the season his powerful attacks and leadership made me twitchy. See villains are very important in power rangers