I like the flavour of capturing one enemy's essence to use as a weapon against another.

The text comes out looking small, but it's somewhat deceptive. It's just Journey to Nowhere with two short extra lines. And hopefully the mechanics are very easy to grok given how familiar the O-Ring effect is these days.

I like this quite a bit, too. And it's more susceptible to removal than Journey, which balances it out with giving something first strike.

­Oblivion Ring and its ilk have some funny interactions with timing that we'll have to be careful of. If I move enchant this on a 1/1 I control, then sacrifice the 1/1 with the enter the battlefield ability on the stack, I'll be able to exile the creature forever. It's true! It's true!

Also of note: This card can enchant and target the same creature, effectively flickering it.

Yeah, I definitely like this. Putting on an aura makes the "when this leaves the battlefield" a lot more relevant.

Reduced cost by one to deal with inherent drawback of auras. I thought about a cost of with the argument that this card is worse than Lance if you only have one creature in play, and worse than Oblivion Ring if your opponent only has one creature in play. But, really, that O-Ring effect is huge, and if there's only one creature in play, do you really need a Lance?

You could argue that this should be , because it's not that much better than Journey to Nowhere and it's a heck of a lot more vulnerable. I'm fine with too though.

Wondering about keywording the ability:

702.X Bind
702.Xa
Bind is a keyword that represents two abilities. "Bind target [object]" means "When this permanent enters the battlefield, exile target [object]." and "When this permanent leaves the battlefield, return the exiled card to the battlefield under its owner's control".

702.Xb
If a permanent refers to "the bound [object]", it refers to the object exiled as a result of Bind's first ability.

Basically means you can write "Bind target creature". And also you can refer to the bound creature's characteristics.

It would be nice if this ablity could read "Exile target creature as long as ~ is on the battlefield". I think that's unambiguous and clear, but doesn't work on the current rules. One possibility would be to change the rules so it does work, another would be to use that as reminder text on a keyword ability.

I've got this nagging in the back of my head that says "If it was so easy to change the rules around Nightmare effects so that they didn't need to write so much each time, wouldn't they have done it already?" I don't know what the problem is, but it feels like pulling out a leg from a pedestal that looks like it will support itself without it... but why would it be there to begin with?

Bind seems cool to me, and I wouldn't be surprised if Wizards didn't do that in the future. I'd be willing to use the wording if everyone else thinks it's a good idea. I personally wouldn't advocate using bound in common... seems like a good way to spread out learning how everything works. See bind at common, see cards that interact with bind at uncommon.

This was a little confusing to remember, since it ties a creature, an aura and an exiled card together (eg. it's inconvenient to put the exiled card face down with the aura), but it was fun, the question of what creature to put it on (one that needs first strike, one that's not going into combat, one that your opponent is less likely to kill) is very interesting, as is the question of when it goes away, but without being too complicated.

Yeah, I agree. It worked well when playing against qqzm whose playstyle is influenced by MTGO: he just put the exiled creature off beside his graveyard. Otherwise it was a little fiddly but did play very well.

As per Jack's comment, this would now read "Exile target creature until ~ leaves the battlefield." Wizard's simplification of this wording means we could now more easily make temporary exile a theme, I think.

And unsurprisingly, Wizards did something quite similar in their enchantment set, Theros. Chained to the Rocks is pushed for Constructed thanks to sharing Standard with Sacred Foundry and friends, but I think our approach here works fine too.

­Faith Unbroken brings the "O-Ring Aura" even closer to this, though they still have it at uncommon.