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http://mythicspoiler.com/rix/cards/waywardswordtooth.jpg

Only time chancellor would be better is a Chrome Mox build to occasionally get 4 mana turn 1.

Volrath's Stronghold or Haunted Fengraf (to stay mono green) seems it could be good to keep up your creatures.

If you want mainboard lifegain, just use Courser of Kruphix.

If you can maintain...