Every good story needs a villain.
In life there is an opposite, like good versus evil; light versus dark; human versus superhuman; man versus woman; dog versus cat; mortal versus immortal, and the list goes on. Without that opposition you have no story.
Batman is loaded with villains.
Lord of The Rings is story full of villains around every corner.
Harry Potter had more than one villain
Star Wars was another series packed with villains.
Then there was Captain Marvel
How about Superman?
I didn't show all the villains but just gave examples for memory recall. Villains can sometimes be the hardest to write about because of their sinister minds. As in real life, good always versus evil, and light overcomes darkness, but you must write about it.
Who is/are the villain(s) in your story? I would love to hear about them.
In my story, The Veil, Maurice Cavalier is the villain/antagonist. He is wealthy, alone, and desires to live forever to enjoy his good fortune. He will go to any lengths to find the fountain of youth, even murder.