Obsessive Pursuit is a rare Enchantment card from Avatar: The Last Airbender Promos (PTLA), collector number 112s. Current market price: — (foil $6.70), TCGplayer market prices via Scryfall.
When this enchantment enters and at the beginning of your upkeep, you lose 1 life and create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.") Whenever you attack, put X +1/+1 counters on target attacking creature, where X is the number of permanents you've sacrificed this turn. If X is three or more, that creature gains lifelink until end of turn.