Magic the Gathering Input

So, one classic element of Magic (from the early days - not ongoing - but any long-time player knows about these, and there is something more subtle that has now taken their place) is the "C-O-P" or Circle of Protection.  When I think of this, these cards are what I imagine:

As you can see, these could be something on the ground or on a stone or wall or door.

We also mentioned hedrons, which are a newer addition to the game, but they played a big role in one set, Zendikar, and they are going to appear again in a set in the near future.  As you can see they can be evoked in a number of ways - highly crafted or quite rugged - they can be floating or earth-bound, or even hidden in a jungle or forest:

Caleb mentioned dryads, though I think you probably have already gone this direction (along with ents)

One element that Caleb didn't agree with me about, in terms of being iconic is the idea of obelisks or borderposts, and he's right, they're not a big element of the game, but they are recognizable, and I think you may have already gone this direction a bit with the standing stones you've mentioned:

The Black Lotus is absolutely THE most iconic card in Magic.  Most players today have never seen one.  They came out in the alpha and beta versions and were "broken" (i.e. too powerful).  They are now worth tens of thousands of dollars each!  Though many players today have never seen one, we all know what a Black Lotus is!

I'm also going to send on some lands that are my favorites.  This is just me talking, not necessarily my boys - though we all love the "island" - but it's not at all subtle, and the key remains subtlety.  You'll see the Magritte influence in this though.  (I don't know if you could hide a hint of this in a strap or something - or have a hint of this, earth-bound maybe, somewhere - if not, no big deal - again going for subtlety!).  The other is a forest, and I just like it.  I don't know that any element of it could be incorporated, but I'm just sending these last two to share a couple of my favorites:

Well, that's quite a lot!  I hope it helps!