This deck is meant to create massive creatures within about 5-6 turns.

Cloudfin Raptor: An early low-cost flyer for blocking or to quickly fly over opponent's defenses by turn 3-4. If I can keep this out on the field, it can become annoying later.

Hero of Leina Tower: A low-cost generator for +1/+1 counters, which combines well with Bioshift, Aqueous Form, Burst of Strength, & Solidarity of Heroes.

Gyre Sage: A good mana/land generator, which combines very well with Burst of Strength & Prophet of Kruphix, and can support X-cost cards Hero of Leina Tower & Nimbus Swimmer.

Korozda Guildmage: A flexible card which can allow one or two of the massive creatures to get through an opponent's defenses via intimidate. It is also able to change a massive creature into an army of Saprolings, which pairs well with Master Biomancer & Prophet of Kruphix.

Sage of Hours: A game-changing creature which can instantly win if played at the right time.

Vorel of the Hull Clade: Able to double counters for a low cost to assist most creatures. Also a decent blocker.

Nimbus Swimmer: A +1/+1 counter generator, a good flyer, works well with Gyre Sage & Corpsejack Menace. Also usually able to evolve other creatures, such as Cloudfin Raptor, Gyre Sage, & Fathom Mage.

Master Biomancer: Benefits any new creatures being cast, and usually evolves other creatures.  Works well with Korozda Guildmage, Corpsejack Menace, and Sage of Hours.

Corpsejack Menace: A good strong creature for a decent cost. Works well with most cards in the deck, including Bioshift, Burst of Strength, all creatures that evolve, Hero of Leina Tower, Nimbus Swimmer, Sage of Hours, Solidarity of Heroes, Vorel of the Hull Clade, Krasis Incubation, Master Biomancer, & Kalonian Hydra.

Prophet of Kruphix: A good utility card, which allows creatures to become stronger on opponents' turns as well. Essentially doubles the rate at which creatures grow.

Kalonian Hydra: The late-game star of the deck. Its trample has the ability to wipe out an opponent the next turn after it is cast (no haste...).

Sapphire Drake: Able to help other creatures get through opponent defenses.

Fathom Mage: Another game-changing creature which can instantly win if played at the right time. Lots of +1/+1 counters should be moved to it on the opponent's turn, so that you may draw many cards and play whichever ones you want to, with a fresh untapped supply of lands, before you need to discard them at the end of your own turn.  Works extremely well if the Gyre Sage and several +1/+1 counters are already on the field.

Krasis Incubation: A single reusable card to stop an opponent's ugly creature dead in its tracks, or improve your own.

Predator's Rapport: Usually much-needed by the time it is drawn. Good for gaining a very large amount of life.

Mana Bloom: Good for an extra land of ANY color each turn.

Aqueous Form: A cheap permanent enchantment to get a single massive creature through any opponent defenses.

Burst of Strength: Cheap instant to generate a +1/+1 counter and re-use a creature as a blocker, or to re-use a creature's tap ability. Works very well with Hero of Leina Tower, Gyre Sage, Sage of Hours, & Vorel of the Hull Clade.

Solidarity of Heroes: Good for doubling one or several creatures' +1/+1 counters. Works well with Hero of Leina Tower & Corpsejack Menace.

Bioshift: A staple card in the deck. It allows counters to be readjusted at any time for any reason. It can also be used defensively on opponent creatures. Works very well with Hero of Leina Tower, Corpsejack Menace, & Fathom Mage.

Treasured Find: The re-do card, good for reviving a game-changing creature or spell. Extremely annoying to opponents when used to recycle Bioshift, Fathom Mage, Sage of Heroes, or Predator's Rapport.

Simic Charm: Mostly in this deck for the hexproof to all creatures until end of turn. Also useful in some cases with returning a creature to its owner's hand.