The arcana oneshots

(Headcanon) The main six(guys) react to MC turning into a mermaid

Julian: "WOAH! Where did that thing come from?" He'd be in awe with your new tail. Also would %100 carry you around To the nearest bathtub to keep you company and not lonely in the ocean. Snacks would also be brought by him almost every night. He'd love to swim with you every once in a while as well!

Lucio: Lucio would dedicate an entire pool by the garden for you so you could swim around without trouble. Would visit everyday and try to prevent the dogs from jumping in and swimming with you, of course it won't work. Also on your birthday he would buy you little pool toys as a playful joke.

Muriel: would find the nearest lake or pond for you and wouldn't like having you stuck in a bathtub all by yourself. He wouldn't get in often but would sit at the edge of the lake to keep your company. Inanna would also jump in and swim around to the best of her ability and be fascinated with the sudden tail you have.