Ghidorah's Gravity beams: essentially just lightning. It can't really be directed and seems more explosive, but lightning for the most part.
Destroyah horn: Just energy that makes his horn more deadly don't know the exact mechanics around it as they aren't ever explained as something to do with the oxygen destroyer.
King Caesar's eyes: 1 Eye can aborb a beam while the other redirects it. It's only been used against mechagodzilla so not sure if Godzilla's atomic breath, or ghidorah's lightning would work as they aren't exactly beams. He can also apparently absorb sunlight according to Godzilla Unleashed.
Gigan's eye beam: The original beam came from the gem on his forehead but was never seen in a movie. In finals wars he shot a beam out of his eye the would spit apart when it hit the targer, or was around the target and hit them all over rather than 1 direct area.
Godzilla's atomic breath: concentrated radiation
