Black Dragon Rising

This Skill can be used if you have at least 7 Level 5 or higher monsters in your Deck.
[REQUIREMENT] Can be activated on turn 2 onward by returning 1 card from your hand to the Deck.
[EFFECT] Reveal 1 Black Dragon's Chick in your hand, and add 1 Red-Eyes Black Dragon from your Deck or Graveyard to your hand. Then, you can decrease the ATK of 1 face-up monster on your opponent's field by 400 until the end of the turn. Your Level 7 Effect Monsters cannot attack this turn.
Other Source
GR Festival Celebration