Why not just "put a permanent card from among them onto the battlefield"? Why make people have to remember all the rules text on, say, Mirko Vosk, Mind Drinker when the card is gone away?

Reminds me of Summoning Trap. Might need to be a bit more expensive.

Technically, can put a Fireball on the battlefield. Granted, that fireball will be very sorry that it's on the battlefield, and promptly die of embarrassment, but I assume you want the words 'permanent card' on there somewhere.

For what it's worth, I agree with Alex. I don't really see the benefit of forcing memory issues, when we can just use the card itself.

Oh, also, this is an enchant creature that doesn't do anything that a sorcery couldn't do. In fact, being an enchant creature makes this card vulnerable to a Doom Blade in response.

Fixed

Not really fixed the main problems, which are that this is a sorcery masquerading as an Aura, and that this creates very complex tokens while simultaneously removing the original card reference for those tokens.

This is what I think this should say (if you want to keep it as an Aura):
"Enchant creature. When ~ ETBs, reveal the top X cards of your library, where X is the enchanted creature's converted mana cost. Put a creature card from among them onto the battlefield, the put of the rest of the cards revealed this way on the bottom of your library in any order."
As Alex has said, creating token copies of creatures or other permanents when there's nothing to reference can cause some memory issues. That's why things that create token copies of things not already on the battlefield, like Mimic Vat or Back from the Brink, tend to remove the copied card to a public zone.