If the "dreaming god" (Big W) were in the Halo game, it would more likely be in Threshold the gas giant or the moon Basis rather than in the Ring. At least the only bodies known to "house" the critters are a sun and the Earth, which are more massive (at least their mass distribution is greater than any cross section of the Ring). Perhaps Threshold can be forced to begin a stellar existence by inducing fusion reactions within it, the Ring can focus energy from it and onto Basis where the Big W (yes, I can't spell it) can be aroused and the destruction of the combined Covenant fleet occur at that time.
Would make a cute cutscene anyway. ;-)
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