Ten Terrors

The Ten Terrors of the Underworld are ten god-like demons/monsters and the most powerful servants of Octomus.

They supposedly only existed in the worst of nightmares but were discovered by Necrolai, dwelling in the Lower Sanctum of the Underworld. They are all normally giant in size, especially in their lair but they can change their size at will to match the height of the Rangers. They are adamant about upholding the Laws of Darkness and are willing to kill each other (and be killed) for transgressing them; it appears that if they don't follow the Rules, there will be dire consequences for them and they may be banished. Their cardinal law is that those who oppose dark magic are to be punished (and then punished and punished some more). They appeared on Earth to demonstrate their power and announce themselves, and easily decimated the Manticore Megazord.

In their lair stands a giant stone monolith known as the Stone of Judgement which projects a ball of light that passes over the Ten Terrors, stopping on the weapon of whoever is chosen to punish Earth next. They waited for Octomus' return, but after the destruction of Imperious emerged to challenge the Mystic Rangers in search of The Light, the one being who could thwart the Master's plans.