Honest (SDBE-EN017) [Structure Deck: Saga of Blue Eyes White Dragon (2020 Date Reprint)]

During your Main Phase: You can return this card from the field to its owner's hand. During either player's Damage Step, when a face-up LIGHT monster you control battles: You can send this card from your hand to the Graveyard; that monster gains ATK equal to the ATK of the opponent's monster it is battling, until the End Phase.