The Time Lords have decreed that the Kryptonians, Asgardians, Celestials & The Green Lantern Corps are a threat to the Multiverse. And have decided to annihilate them by any means necessary.
Negotiations between The Time Lords & The Celestials have failed: And The Time Lords have had enough of the Celestials meddling. And have sentenced them and all who help them to death. In retaliation The Celestials have called forth the Kryptonians, Asgardians & Green Lantern Corps to assist them.
The War happens across the Galaxy.
The Time Lords have access to everything: Including the Angels of Gallifrey.
The Kryptonians have access to everything: Including Superman, Superboy & Super Girl
The Asgardians have access to everything: Including Odin & Thor
The Celestials have access to everything: except Scathan,Tiamut & T-O-A-A.
The Green Lantern Corps have access to everything except: Ion