Who could be the main antagonist in 'mal is a mermaid fanfiction'?

It could be a human fisherman who has discovered a way to capture mermaids and is hunting them down for their valuable scales and tails. Aquata has to stop him before he wipes out all the mermaids in the area. Or perhaps an ancient sea monster that has been awakened from a long slumber and is causing chaos in the ocean, and Aquata is the only one brave enough to face it. This sea monster could be very difficult to defeat as it has powers that are unknown to the mermaids.

A sea witch could be a great antagonist. She might be jealous of Attina's beauty and grace, and try to use her magic to turn Attina into an ordinary fish. The sea witch could also create all sorts of obstacles for Attina and her friends, like summoning sea monsters or causing storms.

A powerful sea witch who is jealous of Marina's beauty and popularity among the mermaids could be the main antagonist. She might try to steal Marina's voice or tail to make her powerless.

A powerful sea sorcerer could be the main antagonist. This sorcerer might be jealous of the little mermaid's beauty and Octvius's unique powers. He could try to create chaos in the underwater world by stealing the magic that keeps the balance in the ocean. He might also try to turn the mermaid's friends and family against her and Octvius, using dark spells and illusions.

The sea witch could be the main antagonist. She might see the Little Mermaid's new - found toe - wiggling ability as a threat to her own power. Maybe she wants to steal the power for herself or stop the Little Mermaid from using it to gain more influence among the sea creatures. So she creates all sorts of obstacles and traps for the Little Mermaid.

A human pirate could be the main antagonist. He accidentally discovers the scepter during a shipwreck and realizes its power. He then decides to use it to control the sea and all the creatures in it. The mermaids have to stop him from using the scepter in such a wrong way.

It could be an evil sea witch. She might be jealous of Lucy's newfound mermaid powers or her connection to the Fairy Tail guild. The sea witch could try to steal Lucy's powers or use her to gain access to the land world.

It could be a dark sorcerer who wants to drain the magic from the enchanted lake for his own evil purposes. He might be jealous of the good magic that Ben and Mal possess and try to stop them from protecting the lake.

A mermaid named Nami could be one of the main characters. She might be a curious and adventurous mermaid who is the first to approach Naruto. Another could be Marina, a more reserved mermaid but with great wisdom. She could act as a sort of advisor to Naruto within the mermaid world.

I think it could be one of the more morally upright contestants like Zoey. She's always been a good - hearted character and would be likely to oppose Mal's evil plans.