Nice. An Eternal Dominion that you can sacrifice. May be a bit undercosted: it's basically Followed Footsteps but better in two ways (not restricted to one creature, and doesn't die if the enchanted creature dies) and only worse in one (can't copy tokens). But still, fun card.

I think the ability should be worded:

> At the beginning of your upkeep, put a token that's a copy of target nonlegendary nontoken creature onto the battlefield.

If I start messing with wording, I'll end up with an aura that enchants worlds, or something. Per cost; I thought the limitation was pretty good - after all, you need some on-board way of removing it and your opponents can mess with that before you're ready. But yeah, the ability to copy whatever new fatty the opponent plops down is pretty powerful.

My only concern would be that you just set up a Magic game in which you have little active participation. You're just going to clone whatever the best thing your opponent has each turn. I'm quite plenty of people will like that, anyways. My favorite strategy in chess, after all, is to just mirror my opponent's moves square for square until they mess up.

Given this set, I wasn't sure if this was supposed to do as Alex said, or have a Momir Basic-inspired effect.

Oh. Bwahahaha. Yes, if the word "choose" was instead "name", that'd be hilarious, but unfortunately also pretty broken. "I'll have a Sphinx of the Steel Wind, then next turn an Inkwell Leviathan, then an It That Betrays..."

That would be rightly epic though. At cost 8, probably printable. In fact, I'll go put that don in card form now.