I think sanctuary does too much and is too bad at what it is intended for: protecting your quanta and hand.
Why would you pack sanctuary? To protect you from pest, nightmare, blackhole and silence. The problem is that out of those it only works against silence.
If you face pest or nightmare, there will be steals -> useless
If you face blackhole, there will be SoF -> useless
And if you want healing you have miracle, luciferine and SoD which all do a better job.
My suggestion: make sanctuary protected and loose the healing. That way stacks wont give you a benefit, but once you have it out you actually get the protection you wanted (maybe make it a shield, it would fit the concept better anyways).
It would be like purify: you dont take it for the healing, it would be good at what it does even without that. You use it to stop the poison or SoSa immediately, thats what it is there for.
If you think it would be OP then, make it two seperate cards (again, does too much), one for quanta protection and one to protect your hand.
Tell me what you think.