This is a resilient aggro deck anchored by a pair of MID one-drops: Willow Geist and Deathbonnet Sprout
. You probably already figured out the strategy here just by looking at those two cards - fill the graveyard with things that can be cast there, and beat the opponent down with efficiency and value.
THE BREADWINNERS
Deathbonnet Sprout
: This adorable shroom is the ideal turn one play for the deck to get some early mill going. When he flips, which is possible by turn 2 and quite possible by turn 3, he becomes an efficient beater that grows every turn, and each card he exiles from your graveyard feeds Willow as well.
Willow Geist: Grows to absurd sizes in this deck if left unchecked, with trample ensuring that it doesn't go to waste, and there are plenty of ways to dig for them until one sticks. A total of 21 other cards in the deck directly add counters to Geist, and most of the others do the job indirectly.
Ominous Roost: While Willow & Sprout are the brute force plan, Roost pays off in a similar way to Willow while creating a wide & evasive army and being harder to remove.
FILL ER UP & FLASH IT BACK
Otherworldly Gaze: Efficient way to fill up the graveyard fast while scouring through the library, & offers a cheap trigger for Willow/Roost as a Flashback spell. If you're feeling lucky with Sprout, try it on your turn 2 upkeep, or any other turn you really want to make sure Sprout flips.
Tapping at the Window: Another efficient way to fill up the graveyard and dig for threats, but for one extra mana it replaces itself in the hand.
Suspicious Stowaway
: Evasively pecks away at the opponent while essentially drawing an extra card every turn, as long as you have one of the plentiful flashback or disturb spells in hand.
Eccentric Farmer: Pretty darn good value for a common, offering a decent & disposable defensive body while getting a few more cards in the yard, a land in hand, and a Willow trigger to boot.
Wrenn and Seven: Just a one-of due to its high cost for an aggro deck, but it can be ramped out as early as turn 4 and its plus drives serious card advantage via spells in the graveyard.
Rootcoil Creeper: The perfect dork for a deck like this, as it helps pull off big turns with its ability to tap for 2 on graveyard spells, plus it helps accelerate things early.
DO DISTURB
Malevolent Hermit
: Play its front side to help protect valuable creatures from removal or trade for value against other aggro decks. Or just discard/mill it to get right to the fun part.
Covetous Castaway
: Solid early defender while Willow & Sprout are growing up, and upon his death he takes a few more cards from the deck with him. His expensive disturb cost is well worth it for Willow as his shuffle trigger results in an extra counter, plus it can recycle a card like Wrenn that got unintentionally milled.
A SMIDGE OF TECH
Quandrix Command: A beautiful tempo card that can help to either catch up or deliver the knockout blow. As an added bonus, it can also shuffle important spells back into the deck if needed, triggering Willow in the process.
Ravenform: We need at least some kind of removal, and this is the best it's gonna get in Simic. Luckily, this deck goes through a lot of cards, so we should still have a good chance at getting either this to deal with a threat or Command to slow it down.
