The main-event of Kairyu Daikessen is an extended kaiju beatdown between dragon and toad, with a castle destroyed in the process.
Kairyu Daikessen is actually more available now than it ever was back in the day. Beautiful widescreen subtitled editions are floating the trader seas under titles like “Dragon Showdown.” The only legit US release is burried on a double feature disc with a Gamera flick, and it’s the pan and scan AIP dub. The American version has it’s charm though, as all the monster “voices” were replaced by ones more familiar to US audiences (Godzilla, Rodan, Ebirah included).
Here’s some additional ephemera from the rare but beloved film: