What happens if you don't have any cards in your deck? Does Lost Ranger get autodiscarded or would his ability not even be able to initiate? I'm leaning more towards the latter, but not really sure.

I would say that his ability initiates, but it does not resolve succesfully. Since it is not possible to define "that card", I guess it just fizzle

That's what I was thinking as well. Since it can't resolve, he doesn't get discarded.

Bolanzo is correct. The ability technically initiates, but since there are no cards, you create a "nil" situation. Under the new(ish) entry in the FAQ, you cannot make the required comparison in the "nil" situation, so the resolution is unsuccessful.

You were probably confusing yourself because in the old "nerfbrokenloyalistnow" days, an empty deck would have ended up with a discarded Lost Ranger.

Yeah good point on the change to the null =/= 0 rule.

OMG what hijinx do you have up your sleeve now asking a question like that. Clearly you have some seedling of an idea.

Nothing. There is nothing there. Don't even think about it! ?_?