There's a scene where a winged monster "Gyaos" shoots a laser beam out of his mouth. The ray bounces off of the blade on "Guiron"s face (sword face monster) back at Gyaos's leg severing it at the knee. Gyaos stands there for a good minute on one leg with no problem.
The whole movie is roughly this insane throughout, as are most of the Showa era Gamera movies.
Another Gamera monster named Barugon. (not to be confused with Baragon from Toho.)

btw that rainbow is coming from his back and is an attack...