Dimir Ninjas
A Legacy deck, by Flugel310
1st place at a tournament in Magic Online on 2020-06-05

Maindeck:

Artifacts
4 Retrofitter Foundry

Artifact Creatures
4 Ornithopter

Creatures
4 Changeling Outcast
4 Ingenious Infiltrator

Instants
4 Brainstorm
3 Daze
3 Fatal Push
1 Force of Negation
4 Force of Will
1 Murderous Cut

Legendary Creatures
3 Yuriko, the Tiger's Shadow

Sorceries
4 Ponder
3 Preordain

Basic Snow Lands
4 Snow-Covered Island
2 Snow-Covered Swamp

Lands
1 Bloodstained Mire
1 Misty Rainforest
4 Polluted Delta
4 Prismatic Vista
2 Underground Sea

Sideboard:
2 Engineered Explosives
2 Embodiment of Agonies
1 Plague Engineer
1 Dread of Night
4 Leyline of the Void
2 Liliana's Triumph
1 Surgical Extraction
2 Thoughtseize