Psycho Rangers

The Psycho Rangers were created as evil counterparts to the Space Rangers.

The evil princess Astronema created them to draw on the power of her master Dark Specter, and they were designed to hunt down the Power Rangers by tracking their energy, voices, and communicator noises. Each Psycho Ranger had a specific fighting style unbeatable by the Ranger that they were evil versions of. The Psycho Rangers consisted of Blue, Yellow, Pink, Black, and Red Psycho Rangers, with the Red Psycho Ranger as their leader. In this way, the Psycho Rangers were used by Astronema not only to defeat the Power Rangers, but also to severely weaken Dark Specter, whom Astronema wished to overthrow. Unfortunately for her, the Psycho Rangers were impatient and unwilling to follow her carefully laid schemes, and were destroyed by the Space Rangers when they discovered that when fighting a Psycho Ranger that was not their color, they could be easily defeated.

The Psycho Rangers were rebuilt and it's revealed that they also had monster forms known as Psycho-Monsters whenever one of them has their Ranger form destroyed:

Psycho-Monster Red is a fire monster. Psycho-Monster Black is a rock monster. Psycho-Monster Blue is an ice monster. Psycho Monster-Yellow is a lizard/hornet monster. Psycho-Monster Pink is a plant-like monster.

Psycho-Pink was the first to become monstrous (by way of becoming a giant), then Psycho-Blue is the second, and Psycho-Red, Psycho-Black, and Psycho-Yellow become Psycho-Monsters at the same time. They ended up destroyed again. Oddly enough, only Psycho-Blue became a giant via the launching of the Satellasers. The others grew by themselves.

The spectral forms of the Psycho Rangers were later restored to life again within Secret City, and attacked the Power Rangers. They turned into their monster forms again but remained human-sized. The Rangers managed to digitize them, preserving them in several key cards.

A year later, these cards found their way into the hands of Deviot, who revived the Psycho Rangers. He sent them after the Galaxy Rangers, but the Space Rangers teamed up with the new generation to defeat the Psychos. Psycho Pink survived, and managed to destroy the Pink Space morpher, replenishing her power. She turned into her monster form and then became a giant once more. The Rangers destroyed her permanently using the Astro Megazord and Galaxy Megazord, but at the cost of the Pink Galaxy Ranger's life.