olympians vs valar

in a amazing event some universe have mixed, the gods of both universe wonder what is the meaning of this. soon, the olympic gods in the search for answer come across with some marvelous creatures that claim to be inmortal spirits in the service of the creator of all. zeus, take this as an insult to his rulership of the skies and defy this true god to show himself but the spirit as his service try stop zeus and fight him. seeing their brother engaging battle hades and poseidon help him in his battle.....

 
zeus

poseidon 
and hades  
vs

manwe 
ulmo 
and melkor( just for the sake of it)

Mmmh. Good question. If they are of different universes. But isn't Iluvatar the same as One-Above-All the Supreme Being of the Marvel Multiverse?

I would rather have the Valar als gods, because they are not as haughty as the Olympians.

So, lets see:

The Valar where directly created by Iluvatar and are older than Ea, the World-That-Is, the Olympians where born and the World-That-Is was already there. Manwé was directly created by Iluvatar, Zeus is just the son of Kronos. The Valar created Arda (equivalent of Earth), the Olympians did not create Earth.

With the power given by Iluvatar (Flame Imperishable) the Valar hold more power than the Olympians who just hold power of their ancestry, which may be dwindled. Also the Valar have the back of Iluvatar, so if things go dire, Iluvatar would intervene and pass His judgment and that would be in favor of the Valar.

O and just to be correct: The equivalent of Hades is Namo Mandos, Lord of the Halls of Mandos, Lord of Death, Judge and Doomsman of the Valar.