This is a pretty cool card. It gets around a lot of the more annoying methods of staying alive, like SoG, Stoneskin, bonewall/dimshield/other 100% shields, and so on. The only concern I have is that if this shard can stack, it would probably get a little ridiculous. Under the current nonstacking system, I think it would be fairer, since playing these would mean you can't have out as much of your other stuff, but with shards stacking, it will be almost impossible to fill all your permanent slots, unless you REALLY try. (or have a ton of mindgates) It probably needs some sort of restriction to prevent being too ridiculous, but I'm not exactly sure what yet.