Godzilla vs. King Ghidorah

Ghidorah just won't die. This is the fourth of fifth flick he's shown up in, and somehow the Big G never has the nerve to off the three-headed two-tailed no-armed winged space dragon. Here's the deal. People from el futuro arrive to tell us that G will destroy Japan if he isn't gotten rid of soon. You think the Japanese would be a little jaded about it at this point, but of course they get scared and help the Futurians go back in time to kill the Godzillazaurus in 1944, before the atomic bomb tests could mutate into G. Mission accomplished, but instead, when the people come back to '91, King Ghidorah's running the show due to Futurian treachery. Now Japan nukes the slumbering Godzilla (although wouldn't he be nonexistent after having been retro-murdered in '44?) Godzilla beats Ghidorah. Godzilla runs amuck. Japanese enlist Ghidorah to smash G. Ghidorah runs amuck. Now the Big G has to whomp Godzilla, I think, all these twists get me confused. Ghidorah comes back as Mecha King Ghidorah and both fall into ocean or some other convenient device. Favorite line has to be American naval officer after watching Godzillasaurus perish: "Take that, you dinosaur!"