Who could be the antagonist in a 'boy gets hypnotic powers story'?

The story could start with the boy being an ordinary kid. One day, he comes across an old, strange object. When he touches it, he gets hypnotic powers. He then decides to use these powers to help his community. He might hypnotize people into cleaning up the neighborhood or being more friendly to each other.

Once upon a time, there was a boy named Tom. One day, he found an old amulet in the attic. As soon as he touched it, he got hypnotic powers. He could make people do simple things like dancing or singing just by looking into their eyes. At first, he used it for fun at school, making his classmates do funny moves. But then he realized it could be misused, so he decided to keep it a secret and only use it for good, like helping a shy friend become more confident by hypnotizing him to believe in himself.

It could be another character who is jealous of Lucy's new powers. Maybe a classmate or a rival in her community who wants those powers for themselves and will do anything to take them from Lucy.

Maybe the main antagonist is an old enemy of Robin's who becomes jealous of his new powers. This enemy then devises a plan to steal Robin's powers or at least neutralize them so that he can regain his former status as the top threat. He could be a powerful martial artist or a criminal mastermind with a large network of henchmen.

A dark entity from another dimension could be the main antagonist. It senses Anna's new powers and wants to use them to open a portal between dimensions so that it can bring its army of monsters into Anna's world. So it constantly hunts Anna down, trying to either force her to use her powers for its own evil plan or simply kill her and take the powers for itself.

A new character could be introduced as the main antagonist. Maybe a powerful alien who sees Kim's new powers as a threat to his plan of taking over the earth. This alien could have his own set of powers that are quite different from Kim's, like the ability to control minds. Kim would have to not only learn to use her new powers but also find a way to defeat an enemy with such a dangerous ability.

The boy could use his hypnotic powers to heal people's traumas. Suppose a person had a bad accident and was haunted by the memories. The boy could hypnotize that person and guide them to face their fears in their subconscious, thus helping them to get over the trauma.

It could be an ancient and powerful wizard. Maybe the wizard sees potential in Beast Boy and decides to grant him new powers to help him in his fight against evil.

A powerful sorcerer could be the main antagonist. Maybe the sorcerer is trying to gather all the meta - human powers for some dark ritual. He targets Beast Boy first because his power of transformation is unique and could be a key component in the ritual. So, he casts a spell that takes away Beast Boy's powers.

Another possibility is that one of Leo's classmates becomes jealous of his powers. This classmate could start spreading rumors about Leo, trying to turn everyone against him. Eventually, the jealousy could turn into something more sinister, and the classmate could team up with some bad elements to try and take away Leo's powers.