S12E15 - Leader of the Whack
Synopsis
A meteorite lands in the forest, gaining the attention of Cassidy & Devin (who were searching for the White Ranger again), Trent (who was on his way out of town), the three DinoThunder Rangers, and Mesogog's newest monster, a weak-willed creature called Rojobot.
Exposure to the "space rock" effects each of them: Trent's Gem-induced schizophrenia is brought under control, Cassidy becomes an acne-faced geek, Devin becomes a Travolta-Fonzie type Disco ladies man, Conner becomes a brainy nerd, Ethan becomes a competitive jock, Kira becomes a fashion and vanity obsessed carbon copy Cassidy, and Rojobot becomes considerably evil. This causes much friction among the Rangers, until Hayley explains the meteorite merely brought out the repressed sides of their personalities.
They manage to work together, destroy Rojobot (with the currently-good White Ranger's help), and shatter the meteorite. All personalities are restored to normal (with Devin & Cassidy nearly kissing each other before it's done).
A fragment of the "space rock" is used by Hayley to attempt to free Tommy from his fossilization in amber. It's a success, but the machine and fragment are toasted, and Tommy's now permanently morphed as the Black DT Ranger!