i like this build but personally i wouldn't use stoic rebuttal if you might not be able to fully take advantage of it. At least take 2 out and replace them with a negate or a psycic barrier. Many quality decks out there run surgical extractions so having alot of one counterspell can sometimes be a liability. On a sidenote you should sideboard exclusion ritual. Its a tad costly compared to oblivion ring but what you remove stays removed and using that with venser could screw up an opponents field real quick in situations where they get alot more down than you can control with your current enchantments. This is a nice build and i think you did a nice job on it hopefully my comments help a tad.
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Personally since this is token based a few parallel lives would probably help support your token growth if you can get the mana for essence that fast.