its unclear how strong the "snarl" in the fabric of reality is on an objective level.
Could be possible to guess. Looking at the Divine Rules SRD, we can guess that Thor and the like would fall in the range of
16-20 Divine Ranks, varying between gods. They all clearly have worshipers that number in the millions - stated
here that there are 10 million dwarves alone, mostly worshiping Thor. Hel, starved of worshipers and souls, probably rates a lower Divine Rank. The Snarl could qualify as an "overdeity"(DR of 21+) - even the SRD's description of an overdeity eerily correlates to the Snarl:
These entities are beyond the ken of mortals and care nothing for worshipers. They do not grant spells, do not answer prayers, and do not respond to queries. If they are known at all, it is to a handful of scholars on the Material Plane.
It seems that when the various pantheons combine their powers, they can create something of a higher Divine Rank than any of them. It could be translated directly from the number of
colors used in the process, since The Dark One is a single god with a uniquely-colored quiddity, yet alone could tip the balance against the Snarl if his power was added to the other pantheons. I suppose a two-color Snarl would rate a lower DR than the current Snarl, but still stronger than any of the other gods.
As for actual stats and abilities, a few things can also be guessed at. During
Hinjo's crayon exposition it was theorized that the Snarl has an ability that gives it a bonus against Divine beings. In the same exposition, it's described as having claws, and possibly the Cleave feat since it killed two gods in one round.