Simic Flash
A Standard deck, by Evan Moore
2nd place at a tournament in Spring Lake, North Carolina, United States on 2019-12-28
As reported at http://www.starcitygames.com

Maindeck:

Creatures
3 Brazen Borrower (Not currently legal in Standard)
4 Frilled Mystic (Not currently legal in Standard)
2 Hydroid Krasis (Not currently legal in Standard)
4 Nightpack Ambusher (Not currently legal in Standard)
3 Paradise Druid (Not currently legal in Standard)

Instants
1 Aether Gust (Not currently legal in Standard)
4 Growth Spiral (Not currently legal in Standard)
2 Mystical Dispute (Not currently legal in Standard)
3 Opt (Not currently legal in Standard)
3 Quench (Not currently legal in Standard)
2 Sinister Sabotage (Not currently legal in Standard)

Legendary Planeswalkers
4 Nissa, Who Shakes the World (Not currently legal in Standard)

Basic Lands
7 Forest
7 Island

Lands
4 Breeding Pool (Not currently legal in Standard)
2 Castle Vantress (Not currently legal in Standard)
1 Fabled Passage (Not currently legal in Standard)
4 Temple of Mystery (Not currently legal in Standard)

Sideboard:
2 Sorcerous Spyglass (Not currently legal in Standard)
1 Hydroid Krasis (Not currently legal in Standard)
2 Lovestruck Beast (Not currently legal in Standard)
3 Aether Gust (Not currently legal in Standard)
2 Chemister's Insight (Not currently legal in Standard)
2 Mystical Dispute (Not currently legal in Standard)
1 Negate
2 Return to Nature