card of the soul yugioh Yu-Gi-Oh! - Pure (DB2-EN086) - Dark Beginnings 2 - Unlimited Edition may be 1st or Unlimited Edition Yu-Gi-Oh! - Soul Absorption (THSF-EN049)

While there are other ways to grant this ability to creatureslike with Curiosityhaving an effect that impacts your entire board is critical for tempo decks that rely on cheap and evasive creatures to deal even small amounts of damage

Instant Color tag templates(None) Phantom Interference Spree (Choose one or more additional costs.) + Create a 2/2 white Spirit creature token with flying

Even the lesser holos like Blastoise and Venusaur in PSA 10 can sell for incredible profits

Just casting this will probably give you something back from your graveyard, and if you already have a mill engine going or dredge cards in your graveyard, the hell gates are open