Godzilla vs. King Kong: How it could be done.
Everybody complains that Kong is too small to take on Godzilla but here's the solution.
Its revealed that certain radioactive elements in the Earth are what caused Godzilla and the other Kaiju to grow and its revealed that Skull island had a small amount of it that the Gorilla species on the island were exposed to it and they and Kong grew to a maximum of 50'.
But a descendent of his was exposed to a vaster quantity of it at childhood and resulted in the 200' foot behemoth that could fight Godzilla to a stand-still.