Jason M’s review published on Letterboxd:
It’s a Kaiju, but with ninjas and wizards set in feudal times, how damned cool ain’t that?
The deceitful Daijô Yüki (Bin Amatsu) and his black magic wizard Oroki-Maru (Ryûtaro Ôtomo) assassinate the regional lord sending a boatload of his trusty servants out on a boat with his young son Ikazuchi-Maru. Just when Oroki-Maru’s giant dragon has about to ram the boat and do away with the righteous heir to the throne, a magic bird swoops down, saving him at the last minute. Ten years later Ikazauchi-Maru (Hiroki Matsukata) back in the region to claim his throne and avenge the murder of his parents…
For quite some time the film spends time laying out the lay of the land, coming off as a fantasy chanbara piece before villagers realize who Ikzeuchi-Maru is and make damned sure to tell him so, hence sending him off on his path of vengeance and struggle to reclaim his the honour of his family. Bare with it because just past the hour, it takes a turn into something completely different when a giant toad attack the village turning it into period piece kaiju - because the dragons back, and it doesn’t end there.
If you know your Kaiju, you will recognize a certain sounds, such as the roar of the dragon – yes, its the king of them all, Godzilla! Other stuff is in there if you can spot it, think of it as an added bonus. This is a wonderful film delivering great Toei fun for everyone. Oh, and the better translation of the title is Mystic Dragons Decisive Battle, which kinda makes more sense as it's a dragon and no snakes are to be seen anywhere.