Endbringer Kaiju Fight

Basically, I am looking for any fic where the endbringers fight another giant monster. Some fics that do this.

Dire Worm Giant Robot.

Another Way absolutely colossal plant monster.

What is an Endbringer to an Egyptian God? Slyfer the Sky Dragon.

Plus Heroes are Made, Queen of the Swarm, War Games, WALK, Mutant Deviations, and a few others have Leviathan fight something big enough to tangle with him one-on-one but not in a way that really feels like a giant monster fight.

I will take anything like any of the above but what I am really looking for is something where another giant monster (crossover creature preferred but not required) just shows up and gets into a fight with an endbringer without really being on the Hero's side. So something more like the Heroes are bystanders to a kaiju battle rather than just having one on their side.