The tag team battle in "Welcome to Ninja World": Metabee and Brass begin to fight properly after Ikki and Arika overcome their differences.
The icing on the cake is the final attack. Metabee loses his left arm and is rendered temporarily blind and the Ninjas prepare to stab them from above with their sword. Metabee raises his still-functioning right arm and Brass help him aim. With a few well-placed shots, our heroes win the fight.
The moment when Uchuu Medarotter X first appears at scene, or more notably, Arcbeetle, when Ikki is fighting against Sarami (in an already unfair fight of three medarot against one), just at the moment he also lost Metabee's medal.
The first time Metabee uses the Medaforce; when Robo-Emperor captures Rokusho and was about to destroy him, Metabee's Rare Medal activates the Medaforce. As Metabee fires a Massive Energy Beam, Robo-Emperor was toast.