This deck can use more Phyrexian Arenas, more sacrifice outlets and more of Ravenous Amulet to trigger lots, but otherwise, it has a solid mana curve, with the exception of Rune-Scarred Demon, which I would exchange out for a 5 or 6 mana creature that would hit the board a lot more often.
Here are some solitaire board states.
From the triggers come life gain (and life loss to opponent), and, most importantly, card draw.
It's great to tutor with Rune-Scarred Demon, but it's just too late of a tutor in a real game.
