Actually in some super sentai series, some of their mecha were really destroyed either in the middle of the series or towards the final battle. This is where destruction goes too far that if a crossover happens, I believe a second mecha was built to replace the destroyed one. Again, Power Rangers didn't start the trend of destroyed mecha, Super Sentai did although Saban's era of Power Rangers took it TOO FAR in MMPR. The Flashmen lost Flashking before the final battle. Eventually they lost Flash Titan too before finishing off the final foe Dr. Lee Keflen after the main villain was defeated. The Fivemen lost the Magmabase during the final battle against Vulgyre. Only Super Five Robo remained as Earth's last hope. The Jetmen's mecha were damaged badly after the final battle with Radiguet- apparently Jet Garuda can't be repaired assuming the parts needed are Dimensian. Tetraboy was severely dismantled by Radiguet. The Carrangers lost their mecha in the final battle...