This is a version of one of my oldest combo decks that I've still failed to get right. It's a variation of the Prosper-Bloom decks that came out during Visions & Tempest. The true version of that deck abuses Prosperity and Cadaverous Bloom. Stack your deck with mana accelerators, control, and discard your hand for a huge Drain Life. They were notorious for winning on the first, second, or third turn and they were infamous for being the first "true" tournament worthy combo deck.
I always liked the combo, and I'm not above using wacky combos, but one type of deck I tend to stay away from are combo decks that take your opponent completely out of the game. You'll never see me put together a Mindslaver deck, for example. (And that's an extreme example.)
By substituting Prosperity for Necropotence, all of a sudden the deck comes to life.
1 Multani, Maro-Sorcerer
1 Kiyomaro, First to Stand
2 Loxodon Hierarch
4 Birds of Paradise
2 Drain Life
3 Swords to Plowshares
1 Yawgmoth's Bargain
2 Cadaverous Bloom
1 Ivory Tower
1 Zuran Orb
2 Empyrial Plate
1 Vampiric Tutor
1 Demonic Tutor
4 Dark Ritual
4 Mox Diamond
1 Sol Ring
4 Flagstones of Trokair
Ok, that's a lot to digest.
Put aside every other deck I've posted here on this blog so far. My favorite decks are always the decks that I can add as many 1-of's as possible. Throw in a couple tutors, make sure you have a lot of utility cards, and you get a lot of controlled randomness. This deck won't win every game, but it's a lot of fun when you do.
The real key to this deck is the Necropotence, Spellbook, and Ivory Tower combo. If you get the right draw, you get get it off on your first turn. Cast them all, draw 19 cards, and gain nearly 19 life during your next upkeep while keeping your entire hand.
This is also why there is a single Unmask in the deck. Just in case you're playing someone with counters or Disenchants. Winning comes in two forms. By dropping a Cadaverous Bloom and draining all their life or with a huge creature in the form of Multani, Kiyomaro, or Empyrial Plate.
Note: The second Cadaverous Bloom is in the deck so you won't have to worry about pitching it to Unmask. You always have a backup. You can even rely on Yawgmoth's Bargain if you want to pitch the Necropotence away.
The other card that will probably pop out at you after giving the decklist a quick glance is Cataclysm. The ideal scenario would be a Mox Diamond, Multani, Maro-Sorcerer, Necropotence, a dual land, and maybe even some extra lands Flagstones of Trokair after it's all said and done.
Even if you don't get ideal conditions, with moxes, flagstones, and Tithe, this deck bounces back amazingly well getting you back on your feet.
Like I said, this deck won't win every game, but when you have half of your deck in your hand, a huge creature on the board, and the threat of Drain Life, it's a lot of fun.