I will admit, this was not my standard brew from the beginning. But after trying white weenie and Esper Control, this deck seemed to pop the most. I have been making small changes for about two months, and I originally didn't invite Xenagos to the party, but I'm very glad he showed up.
The cards I knew I wanted from the start were Desecration Demon, Reaper of the Wilds, and Sylvan Caryatid.
Desecration Demon was originally a 4 of in this deck. I believed in him since RtR came out, and he didn't disappoint. It kills control so quickly they can't even Doom Blade it (and they really can't, haha.) Someone did point out that he was a VERY bad top-deck against aggro and RDW, which is the hardest matchup for this deck anyway, so I decided to cut one.
Reaper of the Wilds is insanely underplayed. You probably know, but still. This is probably my favorite card from Theros, (sorry Xenagos!) A resilient 4-drop that can swing against midrange and control without a care in the world, and defends against aggro as well? And it's splashable? Sign me up. I love the interaction with Desecration Demon, as well as Supreme Verdict. Thank you, I will now scry until I find a Sire of Insanity. Goodnight sir.
Sylvan Caryatid is not the new Farseek. Farseek doesn't die to Supreme Verdict and Anger of the Gods and it thins your deck. But Sylvan Caryatid will be a four of in any multicolored green deck until Theros rotates. also It blocks burning tree and scavenging ooze, both of which I think will be a big deal but even scarier together.
Scavenging Ooze smacks aggro around and insults it's mother. It gains you life while taking advantage of the numerous creatures and their frail toughnesses. Usually it blocks two small creatures and then trades with a 4/4 or 5/5. not to mention synergy with Sire of Insanity and the numerous removal spells.
Lifebane Zombie, as said by the great Brad Nelson, deals with everything. Especially things my deck cant handle, such as: Fleecemane Lion, Boon Satyr, Nylea of Heliod, opposing Reapers, and, most of all, Blood Baron of Viskopa. God I hate that card. Also getting a 3/1 with evasion is pretty nice, though it get's boarded out against control for Duress and Slaughter Games.
Master of Cruelties is also very undervalued. It blocks EVERYTHING! Except Fleecemane Lion. This card is enough to make me play a Rouges Passage, but it doesn't need that to be good. Surviving against aggro, or killing control, this card prompts situations where a Rakdos's Return for one is fatal.
Sire of Insanity is the most undervalued card of all. Control cries when it sees this. Midrange cries if I have more creatures than them. It is worse against aggro, usually losing advantage at the cost of 6 mana. But when it's good, it's really good.