Thousand-Year Dragon King Ghidorah

[Your Turn] If there are 5 or more cards under this card, reduce the rank of all battle cards in your opponent's zones by 3.

[Opponent's Turn] At the beginning of the counter phase, you may place 3 monster cards from your discard pile under this card. If you do, [Destroy] all rank 5 or lower battle cards in your opponent's zones 1–5.