Once you’ve completed The Cursed Mermaids in Shin Megami Tensei V, a new quest will be available from the Mermaid NPC. She tells you of a rumor of a goddess in a lake that can lift curses and begs you to find her so that she can save her cursed sisters. Travel to the top of the mountain, where the source of the water is located, and you should see a water spirit named Anahita.
Anahita is sympathetic to the Mermaid’s plight, but she craves the heat of battle. This is where you come in — defeat Anahita, and she agrees to lift the curse for you. Prepare accordingly though, as this boss is several shades tougher than the Pazuzu you fought earlier.
Anahita is immune to Ice and has access to Bufu, as well as a unique Ice move that hits your entire party for medium Ice damage. As such, Ice Dampeners are extremely useful to utilize. Hit her with Agi and Zio spells, as well as a Tarunda if you have it, to reduce how effective she is. As always, Kagatsuhi: Critical is very useful in chunking a big part of her health meter. Once you vaporize this water goddess, she lifts the curse and bids you return to the Mermaid. You also unlock Megami Anahita as a special fusion.