I know they're not going to be liked by many - but I mostly like this cycle of gold mythics that your opponents benefit from. They're iconic.

This one, though - "I'll play. Play four of this, your turn." Seems a little too unbeatable. (Even worse if you drop "Opponent can't gain life" the turn you drop them.)

Yeah, i wasn't to sure about this. Glad you like the cycle. I wanted it to be something with the opponent gains life but i know there are other cards like "IF a player would gain life he loose it instead, so i'm not to sure. I think i'll figure something out, any suggestions on this one would be much appreciated.

See the discussion over on Crag Beetle for what mythics with a drawback need to look like. This sortof works - it's like a scarily effective player-killer that needs to fight through a couple of shields first. But it'd be rather annoying to get it Pacified or killed before it can attack.

Hmm. How about, rather than "unblockable", you give it "protection from creatures"? That's been seen before in white (Beloved Chaplain, Commander Eesha), and recently too (Spirit Mantle, Holy Mantle); blue is the modern colour of weird protections (Horizon Drake); it includes unblockability, but also makes it immune to Master Decoys and other annoying creature-based ways of dealing with it. Plus it just sounds more splashy, which you need on a mythic-with-a-drawback.

I was going to suggest hexproof... Alex's 'protection from creatures' seems just as valid. This isn't the sort of card you want your opponent to have an easy answer to. Personally, I'd never play with this card the way it is written (or, to be more precise, I'd prefer to play with cards that didn't have such a drawback, until the point where this card was too effecient for its casting cost for me to ignore, at which point, I wouldn't play with it because the card is unfair.)

I know this is your design, and I shouldn't go about suggesting completely different cards, but humor me. I couldn't get this idea out of my head:

­
Creature - Elemental
When ~ enters the battlefield, each opponent gains 8 life.
Unblockable, Vigilance
When ~ deals damage to an opponent, that player gains twice that amount of life.
If an opponent has 40 or more life, they lose the game. ­

Intresting design but i think i'll go with what alex said!