S01E48 - Plague of the Mantis
Synopsis
Trini trains with Master Li in a new fighting technique, known as the Praying Mantis style. She's unable to grasp the proper motivation for achieving the stances. Rita sends down a Mantis monster to face her, one on one. This works towards Trini's advantage in the long run, as she masters the technique, and helps her teammates take the Mantis down.