What change(s) should I make to my Magic: The Gathering deck?

I would add in Skithiryx, the Blight Dragonm 4/4 Flying creature with infect for BB3, with haste and regenerate of B and BB respectively. You might also add Phyrexian Crusader, BB1, 2/2 first strike, pro red and pro white, infect. Idea is to make sure you get some poison counters going so proliferate can kill your opponent quick.