Lone Revenant is a rare Creature — Spirit card from Avacyn Restored (AVR), collector number 64. Current market price: $0.22 (foil $0.20), TCGplayer market prices via Scryfall.
Hexproof (This creature can't be the target of spells or abilities your opponents control.) Whenever this creature deals combat damage to a player, if you control no other creatures, look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.