This deck is build on the +1/+1 theme.
The reason I start building this deck was a friend of mine. He played an nice green/blue Commander/EDH deck wilt Prime Speaker Zegana as Commander. I think Vorel of the Hull Clade is a much better Commander.
There are a lot of cards who comes in to play with +1/+1 counters on it. I started collecting cards like Phantom Centaur (protection from black), Phantom Nantuko (Trample) and Phantom Tiger. Not only have they the come in to play with +1/+1, they also have 'If damage would be dealt to them, prevent that damage by removing a +1/+1 counter". For example, play Vorel of the Hull Clade turn 3, Phantom Nantuko turn 4 and use Vorel's and Nantuko abilities turn 5. Phantom Nantuko is a +6/+6 Trampler growing fast each turn, auch!
Spike Weaver gives you the time to relax. One colorless mana and creatures deal no combat damage this turn. How annoying for you opponent. Time to build your army before he get rid of it. Fertilid helps you to solve any land problem and get through your deck / shuffle it.
Next cards in the deck are cards with the Graft ability. Cytoplast Manipulator is fun, especially when your opponent plays a big creature. Just give him +1/+1 as a gift and use Cytoplast Manipulator's ability and he's yours. Vorel will give him the counters to go one all game long.
Evolve is the next thing in. Gyre Sage provides mana, Renegade Krasis more counters and Simic Manipulator gives you creatures from your opponents.
Rise of the Eldrazi has two sick cards that I definitely want in the deck. Enclave Cryptologist for drawing cards and Lighthouse Chronologist for more turns. Vorel gives you the possibility to level them max when they hit the battlefield. Don't forget to enjoy the face of your opponent when you achieve it.
Playing with counters is playing with proliferate. Contagion Engine en Contagion Clasp let you give opponent -1/-1 counters on there creatures. Check for the other proliferate cards my deck. Infect works great with proliferate so I play Core Prowler, Blighted Agent (unblockable) and Viral Drake (multiple proliferate with enough mana).
Experiment Kraj gives you all kind of options. In game together with Voral is madness. Double counter with Vorel, double the double with using Vorel's abilities with Kraj. Hello! Twice the abilities from Cytoplast Manipulator or Simic Manipulator won't make your game less fun.
There is a once in a life time combo in this deck. Liquimetal Coating gives Vorel the option to double the counters on a Planeswalker, in this deck Jace, Architect of Thought. Small chance of playing this combo in a 100 card deck. Fun when you play Jace and use his -8 ability the turn it comes in play.
Hurting your opponent;When all the possibilities above wont get your opponent to madness you have game winners with Champion of Lambolt (creatures your opponent control cant block) combined with infect. You have Crowned Ceratok to give all your +1/+1 darlings Trample. Triumph of the Hordes and Overrun for the finish.
The deck contains only two counters and, use them sensible. Creatures probably wont hurt you, remove or mass damage will. Save your counters. I like cards like Control Magic and Corrupted Conscience to control my opponents creatures.
Last thing; Bioshift is a sick card in this deck. Give Blighted Agent the eight +1/+1 counters from Sekki, Seasons' Guide an double them with Vorel. Bye, bye!
Let me know what you think!