The Official Omegan Ranking:

1) Alucard
2) Voidwalker
3) 5
4) Not-Mia
5) Cosmos
6) Bahamut
7) Toguro

This is their capability in terms of sheer combat potential. Versatility and situational abilities are not applied to this chart. While Cosmos is weaker than 5, he would be far more effective against the Sergal, for example.