Note that Vigor gives you half of this effect for 14 mana cheaper, and Platinum Empyrion gives you the other half and a much larger body for 12 mana less. Even Emrakul, the Aeons Torn] was only 15 mana. (She could perhaps have used a no-cheating clause like this has, I'll admit.)

Also note there are serious problems with cards having a mana cost at or near 20. SadisticMystic already mentioned Erratic Explosion; there's also Riddle of Lightning to make it easier to find your 20-drop. It's a bit too close to enabling an instant-win even if it did have an effect worth 20 mana.

There's also the point that this simply won't fit in the card frame.
By the way, Alex: Emrakul is a SHE? I never knew.

I will try and fix my spirit avatars soon, though I must admit that they're not a primary focus.

@L2i0n0k7: Heh. There was a Savor the Flavor Letter of the Week on this topic, here. The motivation is because the goddess mythos Emeria, based on Emrakul, was feminine (where Cosi and Ula were masculine). The answer is "The Eldrazi are basically 'it', but if you want to call Emrakul 'she', feel free."

Ah. I started playing some time after RoE came out and I didn't get really into Magic until later that year, so there's a large portion of articles I haven't read.