The Anti-power handcuffs are specialized handcuffs that were made for the prisoners with special powers in Super Power Island. You will need these in your backpack to capture them and return them to the prison.
How to get the Anti-Power Handcuffs
You can get the Anti-Power Handcuffs from the woman beside him that wearing the lab coat on the left side of the island where you arrived in the Super Power Island. You also need to get Super Villain Files from the guard with the gray hair and moustache which is the Prison Warden.