Territory of the Sea Serpent King

[REQUIREMENT] Can be activated if all of the monsters in your constructed Deck are WATER Attribute monsters and all of the monsters (except Level 2–4 monsters) are Sea Serpent Type monsters. [EFFECT] Make the original ATK of 1 face-up Level 7 or higher monster on your field become 2900 until the end of this turn. If there is no card in your Field Zone, you can also Set 1 "Umi" from your Deck or Graveyard to your Field Zone. (Once per Duel.)