What a guy!
But!
If the Dark One is a tool (witting or unwitting) of the Snarl, then the Plan is really the *Snarl's* Plan.
So, once the ritual gives the Dark One the ability to release the Snarl anywhere he wants, he (or the Snarl) almost certainly *will* try to kill all of the other Gods (assuming that that really is the Snarl's goal).