The idea behind this deck is to get creatures evolving quickly and for those evolutions to lead to further evolutions. There's also some card draw (with Prime Speaker Zegana, Fathom Mage, and Divination) for keeping options open, and accelerated mana acqirement through Elvish Mystic and Gyre Sage.
Renegade Krasis is the most pivotal creature in the game, since its ability can quicken the pace of the evolutions of all my other creatures. Deadbrige Goliath will mainly help to evolve Renegade Krasis. Kalonian Hydra and Master Biomancer will also contribute to increasing the rate of stacking evolution counters.
Ooze Flux will take counters off of Renegade Krasis (and other creatures, if necessary) to evolve Renegade Krasis, which evolves all other creatures as well due to Renegade Krasis' ability.
Simic Charm is a fantastically versatile card--it can be used for avoiding spells that would send creatures back into my deck (with the hexproof permanents ability), or for combating overly strong enemy creatures (with the +3/+3 ability). Bioshift is similarly versatile: if an opponent uses a kill card on a creature on whom I have placed most of my +1/+1 counters, I can easily move the counters to another creature without many losses.
Cards like Crowned Ceratok, Elusive Krasis, and Kalonian Hydra will ensure that the opponent takes damage through doing direct combat damage to the player.
I've thought about concentrating my cards by cutting out their variety, but this seems counterproductive for an evolve deck, since variations in power/toughness are what drive the mechanic.
Any advice you guys can give me? I've been working on making a good Simic evolve deck for a while, and this seems to work best so far, but I know I can do better, and the evolve mechanic is still rather slow.