Silumgar Assassin

Mana cost: {1}{B}
Type: Creature — Human Assassin
Power / toughness: 2 / 1
Set: Commander 2019 #128 (rare)
Price: $0.35 USD

Creatures with power greater than this creature's power can't block it.
Megamorph {2}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When this creature is turned face up, destroy target creature with power 3 or less an opponent controls.

Silumgar Assassin has 3 printings, first in Dragons of Tarkir (2015). EDHREC ranks it #11,599 among Commander cards. It appears most in Kadena, Slinking Sorcerer decks (5,553 on EDHREC). 1 public deck on TCG runs it. It has 4 official rulings.

Legality

commander: legal
legacy: legal
vintage: legal
pauper: not legal
modern: legal
pioneer: legal
standard: not legal
brawl: not legal

Public decks that run Silumgar Assassin

Faceless Menace - Commander 2019, led by Kadena, Slinking Sorcerer

Commanders that run Silumgar Assassin most

Deck counts from EDHREC.

Often played with Silumgar Assassin

Cards that show up in the same decks on EDHREC.

Rulings

2015-02-25: If a face-down creature with megamorph is turned face up some other way (for example, if you manifest a card with megamorph and then pay its mana cost to turn it face up), you won’t put a +1/+1 counter on it.
2015-02-25: Turning a face-down creature with megamorph face up and putting a +1/+1 counter on it is a special action. It doesn’t use the stack and can’t be responded to.
2015-02-25: The powers of Silumgar Assassin and the creature trying to block it are checked only as blockers are declared. Changing the powers of either of those creatures after Silumgar Assassin is legally blocked won’t change or undo the block.
2015-02-25: Megamorph is a variant of the morph ability. You can find more information on morph on cards with morph from the Khans of Tarkir set.