Hello, and welcome to Grim Allocations, my Lifedrain Orzhov control deck! As always, please +1 if you like my ideas, and all suggestions are welcome.
Part 1: No Allocations For You
The basic idea of this deck is to lock down the board and make it so that any action your opponent takes causes them pain. The keys to this are two KLD cards, Authority of the Consuls and Kambal, Consul of Allocation. Ideally you want to drop the former on Turn 1 to optimize the lifegain and slow down aggro decks as soon as possible. If you can get Kambal on turn 3 as well it will grind any deck to a halt. As for Turn 2..
Part 2: Allies Just Suck The Life Out Of You
Now that your opponent is slowed down, the next step is to get your Lifedrain and Lifelink creatures on the board. Cliffhaven Vampire's main purpose is to sit on the battlefield and activate its abilities, though it is an effective blocker. The lifelinkers should attack at every opportunity to maximize the Cliffhaven's activations.
Part 3: Control, Control, You Must Use Control
The rest of the deck is your typical Orzhov control cards, though one bears mention. Blessed Alliance is crazy useful, because not only does it remove, it can also untap Lifelink blockers or gain you a quick 4.
Finishers: Life of the party
Sorin, Grim Nemesis is a perfect fit for this deck: removal, life gain, and an ultimate that, if you can pop it, will almost always end the game immediately. Otherwise, all the lifegain should pump the Bloodbond Vampires through the roof, and Defiant Bloodlord is a Cliffhaven on steroids, turning every gain of life into a burn spell.
Sideboard:
With all those vehicles like Heart of Kiran around, some nice cheap artifact hate is necessary, so I have 3 of Fragmentize in the sideboard. Lost Legacy comes in against combo decks like Copycat, Declaration in Stone against token generators, and Fumigate and Yahenni's Expertise to wrath away aggro.
Well, I hope you like my ideas! Please +1, and let me know what you think.