I would start off with Dedede turning gigantic and he and both Typhon clash with each other kaiju style causing destruction and destroying the landscapes, under the sea, major cities including New York and others. The opponents move up into the skies getting bigger and bigger forcing them out of Earth and into space clashing with each other through our Solar System using the eight planets, dwarf planets, moons, asteroids and our Sun as weapons, same with random exoplanets, rouge planets and other bigger suns the more larger they get, causing chaos across the Milky Way itself. for the climax finale of said battle, the two reach the center of our galaxy and they fight above and inside the Galactic Center, an apparent dormant supermassive black hole.
(Through the entire fight in space, remember that Dedede and Typhon use entire planets, moons, suns, asteroids, exoplanets, comets and other celestial objects as weapons.)