Quote Originally Posted by Claymore View Post
I think you apply both replacement effects in the order you want. Either way, Vizier -1 (0) then Snake +1 (1) or vice versa results in one counter.

Unless something in the rules comes out that if you hit zero counters then the effect fizzles. Then the order has to be snake vizier, and Devoted Druid doesn't work.
I feel like this is one of those times where the replacement effect is making this more or less like a cost you can't pay and therefore it doesn't end up doing anything.

There's a specific thing I'm thinking of that IIRC used to work but doesn't anymore - something about Leyline of the Void and that creature that says "put an exiled card to its owner's graveyard: get +2/+2 and trample" and so you used to be able to loop paying the cost with a single card and make an arbitrarily large creature. But I think they changed the rules regarding replacement effects in paying costs to keep this from working? Or maybe they changed a different subtlety of the rules and I've just forgotten. Suddenly I'm filled with doubt.

At any rate it's usually a bad idea to guess at interactions for cards that haven't come out so maybe it's best to wait until the prerelease and see if there's anything clarifying.