
Whenever a nontoken creature you control dies, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, create a 1/1 white Human Soldier creature token.
Ulvenwald Mysteries has 9 printings, first in Shadows over Innistrad (2016). EDHREC ranks it #7,964 among Commander cards. It appears most in Morska, Undersea Sleuth decks (3,750 on EDHREC). 1 public deck on TCG runs it. It has 3 official rulings.
Deck counts from EDHREC.
Cards that show up in the same decks on EDHREC.