Created for Challenge # 102. This was going to be "protection from all colours" as a riff on Iona, Shield of Emeria, but then I remembered Progenitus and thought he deserved a revisit for this challenge.

I like "You have protection from everything", but giving the Guardian protection from everything also means... I guess I got to wipe the board? That, and the occasional lucky Innocent Blood I suppose. I'd actually argue that this card is more powerful than Emrakul, the Aeons Torn, and that's saying something.

Well, it can be countered and non-targeted stuff can hit it.

And, as you say, untargetted "All players" stuff, so some small amount of milling and damage can still get past it.

Given emrakul, I guess a flat "Sorcery: Win the game" costs 18+?

Normally, I don't give much credence to 'can be countered', but I guess it matters when comparing cards to Emrakul. Emrakul still grants the extra turn, even if your opponent is packing a Cancel. This is still better, in my opinion, but it does pull Emrakul a little closer.

As for the cost of "Win the game"? I don't know. It's almost a trap question, since acknowledging that a card can do that infers that nothing else can be printed at a higher cost than that card (you know, besides Split Second versions of the card and whatnot). I can think of a few effects you can stick past 15/16 ("You control enchanted player" springs to mind.)

Now that I think of it, it's kind of amazing to think that Magic didn't constantly increase it's mana cost to help balance the game. I mean, it did, kind of. But the game would have been very different if it treated cards like Mishra's Workshop as standard, and ignored the qualms of the collectors. Why play with a normal Mountain, when Turbo Mountains tap to add to your mana pool?

Unconditional "Win the game" will never be printed. Probably. But Door to Nothingness costs 15 in all five colours. And there's all the Coalition Victory variations.