Sequestering Barrier -- WW
Creature -- Wall -- Rare
Sequestering Barrier can't be the target of spells or abilities you control.
You can't be the target of spells or abilities.
If you would choose a target, an opponent chooses that target instead. (It must still be a legal target.)

I'd've loved to use Hexproof here, but I realized halfway through that Hexproof doesn't protect against your own stuff, even if it's not you choosing the target. This is intended to be an alternative to Leyline of Sanctity. I'd give the thing Shroud, but then it's too hard to interact with. I'd give it "You have shroud", but Shroud is deprecated so it seems better to just spell it out.