My submission:
Until end of the turn, target permanent is indestructible. You gain life equal to its total mana cost.
It explores a mechanic that is new to Magic, and the first time in an Instant/Sorcery form. Not to mention how powerful a card like this would be, given the right mana cost, of course, which I envision at 2WW, if not 1WW, and at Instant speed, of course. Not broken, not over the top, just interesting.