Doubling Season or bust.
Who cares if it's $20? It would break this deck in half.
With all the goblins running around Krenko, Mob Boss sounds like a great support player, maybe even a back up win con.
Also I am wondering if you have enough token generation that Burn at the Stake would be a good inclusion.
Its good because he taps 5 creatures, then 10 to conspire, thats 75 damage. so its silly. Burn at the stake is a good addition
I would add Doubling Season for maximum prophet.
I love Wort, here is a suggestion from the deck that I played and had plenty of success with: Wake of Destruction This card is a little mean, but when you can take out all Islands, Plains, or Swamps and then do it again fun things start happening . Also you may have more success running Garruk Wildspeaker over Tibalt, the Fiend-Blooded .
card:Horncaller's Chant Could be a nice new addition, sure it cost 8 to play but if you copy it once you get 16 power and if you copy it more than once well the sky is the limit.