It could also be part of a larger, more complex plot. The kidnapper might be working for an organization that needs Lucas for some special ability he has. For example, if Lucas has a unique power in the fanfiction, they could want to use it for their own evil purposes.
The masked man might kidnap Lucas for ransom. Maybe Lucas comes from a wealthy family in the fanfiction world, and the kidnapper sees an opportunity to get a large sum of money.
Lucas could try to find a weakness in the masked man's security. If he's tied up, he might look for something sharp to cut the ropes. Maybe there's a broken piece of glass or a rough edge on a table in the place where he's held captive.
Maybe he's a bounty hunter hired by someone who has a grudge against Lucas. This someone could be a powerful villain who wants Lucas out of the way. The masked man is just doing his job, but as the fanfiction progresses, he might start to question the morality of his actions.
One possible plot could be that the masked man has some vendetta against Lucas. Maybe he's from Lucas's past, an old enemy. He captures Lucas to get some sort of revenge or information. In the fanfiction, Lucas could be a heroic character, so his friends might start a rescue mission. The masked man could be holding Lucas in a secret lair, filled with traps and puzzles for the rescuers to overcome.
One possible motive could be to use Hermione as a bargaining chip. Maybe Narcissa wants to exchange her for something important to the Death Eaters, like information or the release of a captured Death Eater. In the wizarding world of 'Harry Potter', such power - play is not uncommon among the dark forces.
One possible motive could be to gain an advantage over Harry Potter. Hermione is Harry's closest friend and a very intelligent witch. By kidnapping her, Draco might think he can use her as a bargaining chip to make Harry do something or to get information from her that could be useful to the Death Eaters. Another reason could be jealousy. Draco has always been in competition with the Gryffindors, and Hermione's intelligence and skills might make him envious to the point of doing something drastic like kidnapping.
One possible motive could be that Lex Luthor sees Superboy as a threat. Since Superboy has super - powers, Lex might want to study him or find a way to control him. Maybe he plans to use Superboy's powers for his own evil schemes. Another reason could be jealousy. Superboy is often seen as a hero, and Lex Luthor, being a villain, can't stand someone having so much power and adoration.
Another motive could be that Uncle Phil has some sort of secret that he thinks Jamie has discovered. He might be worried that Jamie will expose this secret, so he kidnaps him to keep him quiet. This secret could be something related to the family's past, like a hidden treasure or a dark family secret that Uncle Phil wants to keep buried.
The masked man could be a new character created specifically for the fanfiction. He could be a ninja from a far - off land who has come to the Naruto world with a hidden agenda. He wears the mask to blend in and observe the different ninja villages. Another possibility is that it's a reincarnation of a powerful and evil being from the past, and the mask is a way to contain some of his power while also hiding his true form.
The masked man in Naruto fanfiction might be a character created solely for the fanfic. He could be a powerful shinobi who was experimented on by Orochimaru and now seeks revenge. Or perhaps he's a long - lost relative of Naruto, who was hidden away and now has a different view of the ninja world and wants to reshape it. Another possibility is that he's a spirit or a demon in a human form, with its own motives.
It could be revenge. Maybe the woman did something that made the man angry in the past, and he's taking out his rage in this extreme way.