Wow, TheWrathofShane posted I comment I can agree with!

Rage Extractor
Phyrexian Metamorph (to copy/set off the Rage Extractors/other Metamorphs)
Tezzeret's Gambit
Gitaxian Probe (both will trigger Rage Extractor, then cut down the deck size to find more of them)
Vault Skirge (to regain the life you're paying. He's one of the few lifelink cards where I deem lifelink a "necessary" ability.)
The depletion lands from Mercadian Masques. (or insert land here that uses counters, so they can be fully utilized with Tezzeret's Gambit)
Noxious Revival (to save anything the opponent broke, to save a depleted land or if you want to reuse Tezzeret's Gambit)

And then fill in the holes with a little more lifegain (I prefer Pristine Talisman and Solemn Offering) and big Phyrexian Spells (I prefer Norn's Annex due to its defensive, lif... (see all)