Gragonith, Lightsworn Dragon (SDLI-EN005) [Structure Deck: Realm of Light (2020 Date Reprint)]

This card gains 300 ATK and DEF for each "Lightsworn" monster with a different name in your Graveyard. If this card attacks a Defense Position monster, inflict piercing Battle Damage to your opponent. During each of your End Phases: Send the top 3 cards of your Deck to the Graveyard. You must control this face-up card to activate and to resolve this effect.