Guardian Monsters

The Guardian Monsters were a trio of ancient monsters- Baragon, Mothra, and King Ghidorah- that guard their homeland of Japan (the actual land,not the nation). They were slain by natives 3000 years ago, although their spirits were preserved in stone and given worship.

When Godzilla returned in the early 21st century, the Guardian Monsters were revived (7000 years early) to battle him. Baragon fell early, while Mothra and Ghidorah barely managed to delay Godzilla in Tokyo. Eventually, the spirits of Mothra and Baragon combined to empower Ghidorah, giving Godzilla quite the battle- but ultimately the combined Guardian Monsters fell, merging into Godzilla in a last attempt to stop him. It was left to the Japanese Self-Defense Forces to stop him.