op-8 booster box One Piece TCG: Adventure on Kami's Island (OP-15) 12-Box Case Kureha and Dr One Piece TCG: Royal Blood

28, 2024 A Digimon with a play cost of 9 or less attacked a player, digivolved using a [When Attacking] effect, and became a Digimon with a play cost of 10 or more in a state where this card's [On Play][When Digivolving] effect was activated for my opponent

Forced - At the end of your turn, if you have not dealt any damage this turn: Take 1 horror

When your opponent activates a monster effect, or Spell Card or effect, while "Umi" is on the field (Quick Effect): You can negate that effect, then, you can make this card gain 600 ATK/DEF

This effect is most effective when summoning floodgate monsters, the most synergistic of which being "Amorphage Sloth" - who has the benefit of also being searchable by "Redox" and due to being Level 6 can be Tribute Summoned if the "Dragon Ruler" player has not used their Normal Summon