Nashi, Searcher in the Dark is a rare Legendary Creature — Rat Ninja Wizard card from Duskmourn: House of Horror Promos (PDSK), collector number 223p. Current market price: $0.33 (foil $0.51), TCGplayer market prices via Scryfall.
Menace Whenever Nashi deals combat damage to a player, you mill that many cards. You may put any number of legendary and/or enchantment cards from among them into your hand. If you put no cards into your hand this way, put a +1/+1 counter on Nashi.