When it comes to Magic: The Gathering, one of my favorite experiences is finding a silly concept that has enough support in the cards to become a competitively viable deck. Way back during in the days of the Closed Beta, the deck I played most was based on Muldrotha, the Gravetide. While not a competitive deck, it played well enough and gave me a ton of fun.
While this Simic Flash deck doesn't offer Muldrotha's sheer recursive power, it's in the similar vein of fun concepts that seem like they shouldn't work, but actually gels into a coherent package that can absolutely end games. On top of that, it fits the kind of reactive playstyle that normally gravitates me toward control decks like Esper and Grixis builds.
You check out the decklist here. Since this version is being used in best-of-one matches, I opted to ignore the sideboard, but the main deck is actually pretty cheap, consisting mostly of commons and uncommons (mana base aside).
The most important part of playing this deck is getting to the 4th land (in any combination that can produce UUGG) as soon as possible, and then getting rid of as many lands as possible beyond that. There are two major reasons for this.
First, once the magic number has been hit, the decks two major finishers come into play. Those cards specifically are Frilled Mystic and Nightpack Ambusher. The sheer value from both of these cards is not to be underestimated.
In the case of Frilled Mystic, her 3/2 stat line is okay, but even better is the ability to counter a spell without losing a card, instead placing a body on the board. This can seriously disrupt and ruin an opponent's plan while setting yourself up for victory.
A similar case can be made for the Nightpack Ambusher. Even though this deck doesn't run any other wolves or werewolves, the ability to surprise an opponent with a 4/4 in the middle of their combat step (or at the end of their turn when they've exhausted their mana) can completely shatter an otherwise strong attack. And should it remain on the board (which it usually does), the tokens it produces can creature enough power to just win the game. This is usually the card that will ensure a win once it lands.
And yet, despite having such excellent 4-drops, we don't want to have any lands beyond that. This is a tempo deck, which relies heavily on getting into a rhythm while disrupting the opponent as much as possible. As a result, once we get to our desired land count, we want as many playables as we can get our hands on. This is why we run Sinister Sabotage and the Temple of Mystery, since the Surveil/Scry can help us filter our those excess lands (or get to our 4th if we're in the early game). And if we can get mana flooded, Spectral Sailor can help us transform that into card draw in the hopes of getting to the key pieces we need.
The rest of the deck is just strong value at instant speed, including good blockers, counter spells, and ways to bounce creatures back into the hand. Overall, it's a deck a enjoy running quite a bit.