We talked about this mechanic in the Multiverse Design Challenge. Originally, this was a , and that turned out to be insanely oppressive, in ways that you wouldn't guess just by looking at the card. It was a one card uphill battle, than operated a lot like Zuran Orb... it doesn't look like much, but a mysterious 12 point life gain through the process of your limited game without casting any spells is a bit crazy.

It was, however, an excellent wisdom card, since it asked the white player to just hang out and gain life, when casting spells didn't seem critical. Doubling the activation cost and life gain did wonders for the card... the same effect, but harder to get maximum value out of.