Legion ran and ran. They voted on what to do about the strange, identical creatures chasing them. 7 to continue running while 2 voted to do something about them, be it trapping them somewhere, creating a bomb to make them explode, devouring them, or using Chaos energy to submerge them.
While that last part appealed to them as they would be able to see how a world god would fate against Chaos energy, only Aeternus and Ragnarok were for it. The rest of the clones were not willing to risk their lives at all.
It is not even a matter of Legion-7 keeping something from them anymore. They can all see for themselves that things are very serious. It wouldn't have mattered if they had succeeded in killing the first strange being that looks like them. It wouldn't have mattered if they had somehow gotten rid of the second one either.