Works to exploit the pestilence card (and a few other cards with similar abilities). Most pestilence decks I see run either mono black or go black white with pro-black creatures and protection effects. I just know that pestilence can be harnessed better than that and do ridiculous things with green though so he's my effort into making that a reality. Primarily designed for multiplayer where it's effectiveness can really shine, this deck does well one on one as well.
My main sources of a pestilence effect, other than pestilence itself, include Plague Spitters, Thrashing Wumpus, and the beautiful finisher Pestilence Demon.
Coupled with these great black creatures I also put in a whole host of green creatures that do nothing better than respond to damage. Fungusaur, Protean Hydra and Sprouting Phytohydra all serve this purpose perfectly. Protean Hydra's numbers grow exponentially as I start hitting them for damage, allowing me gain outrageous amounts of life with Vampiric Link, or produce insane amounts of green mana with overgrown battlement, all while completing shutting down any kind of ground assault my opponents may throw my way. Better yet, Rite of Passage essentially makes every creature I have a Fungusaur, which becomes insane as I pestilence to wipe the board then swing through unopposed with scary-huge creatures.
Paradise Plume and Pristine Talisman provide me with life to make up for constantly pinging myself with pestilence while at the same time providing me with early-game mana. Sun Droplet gives a nice way of recovering life through each upkeep and Mind Stone gets me some mana early on while getting me a card draw once my mana base is established.
Finally Vampiric link and Keen Sense begin to do completely absurd things when attached to a creature with a pestilence effect. Either draw cards equal to the number of opponents for one black mana with Keen Sense, or gain life equal to the number of opponents plus the number of creatures on the board with Vampiric Link.
Any suggestions, comments, or upvotes are always appreciated!
