This card isn't worth the life loss to me. You happen to draw into a dark dragon when you are low on health and the game is over. No way to get rid of the permanent with ease on your side. I wouldn't use any card that takes life away for extra draw power for the amount of potential damage I could take. Also, terrible if somebody just stalls you. As you are taking damage. Take Sundial for example. The only use I could see for this might be SoS or Nightmare to be effective. Unless you have a ludicrous life gain deck.
You would just have to build a deck around it.
This is actually absolutely perfect for large rainbow decks where most cards would be low cost anyway.
If everything is fairly low cost, then you just have to pack some sanctuaries to make up the difference.
... It would be a little safer if it were an activated ability, but the danger makes a nice balancing effect.
Also, this is a creature so there most definitely IS a way to get rid of it (cremation or liquid shadow would work nicely)
Building a high card count deck out of these, fractals and ball lightneing could be amusing.
