Szadek, Lord of Secrets {3}{U}{U}{B}{B}
Legendary Creature — Vampire
Identity
Dimir
EDHREC rank
#18,872
Cheapest printing
US$0.21
TCGplayer
Printings
4
Flying
If Szadek would deal combat damage to a player, instead put that many +1/+1 counters on Szadek and that player mills that many cards.
Every printing
highest TCGplayer market first; a card with only a thin single listing shows its low
In short
A Commander deck is a commander and 99 other cards, one copy of each (except basic lands), all inside the commander's colour identity. Paste a full list into the deck price calculator to price it and check it against the format.