Retsu vs Moryia in episode 6. This dude is called Fantastic Technique for a reason.
Jan's duel with Maku in episode 35.
Episode 39. MIKI summons and takes control of SaiDaiOu.
The entirety of Episode 47.
The fourth Kensei, Sharkie Chan, gives the Gekirangers a few tests to see how tough their body is for training. First, he flings a series of rocks at the canoe they're in. While Ran and Retsu are exhausted from rowing for the past three hours, Jan's still got power to spare, and deflects every rock coming his way with a boulder. Impressed, Sharkie then sets the river on fire. Jan's response? Stick his oar in the riverbed and spin the canoe around it so fast that the vortex puts out all the flames. Then, Sharkie starts swimming after them Jaws-style (Ran lampshades this), and turns it into a race. When he starts to outpace the canoe, what does Jan do? He breaks the oar over his head and DUAL-PADDLES WITH THE PIECES!