The Celestials verus The Galactii
k, so ALL the Galactuses from all the universes in Marvel face off against all the 616 Celestials.
repeat, only 616 Celestials, there's supposed to be billions or something. and there's an endless number of universes, so there should be a sufficient number of "Galactii" to combat them.
anyway, two scenarios:
1) Galactus neither uses the UN nor consumes the universe but fights the Celestials
2) Galactus going all out