Black Widow usually escapes by taking advantage of her environment. If she's tied up in a room, she'll look for any sharp edges or objects that can cut the ropes. Sometimes, she'll play mind games with her captors. She might pretend to be weaker or more afraid than she really is, and when they let their guard down, she makes her move. Also, she has a great deal of knowledge about different types of restraints and how to break them. So, she can quickly assess the situation and find the best way to get free, whether it's by untying knots or breaking the bindings.
One common plot twist could be that she is tied up as part of a ruse by her own side. Maybe they are trying to deceive the enemy into thinking she's been captured. Another could be that she discovers a hidden power or knowledge while in this vulnerable state. For example, she might figure out a way to break free using some newfound skill she didn't know she had before. And sometimes, the person who tied her up turns out to be an old acquaintance with a complex backstory and motives that are not initially clear.
One possible storyline could be about Black Widow's escape from the tied - up situation. She might use her combat skills and intelligence to outwit her captors. For example, she could trick them into making a mistake and then break free.
Perhaps a new, original villain created by the DeviantArt author. This villain might have some special powers or motives related to Black Widow specifically. For example, if the story is set in an alternate universe, the antagonist could be a powerful magic - user who ties her up using enchanted ropes to keep her from disrupting their magical rituals.
I'm not sure specifically which 'Black Widow tied up' story on DeviantArt you're referring to. There could be various interpretations. It might be a story where Black Widow is in a hostage - like situation and has to use her wits and skills to escape. Or it could be part of a more complex superhero - themed adventure where she's captured by an enemy.
There could be her fellow Avengers who might be involved. For instance, Captain America could be trying to rescue her, using his leadership and combat abilities. His sense of justice would drive him to save her from whatever danger she is in.
One plot possibility could be a rescue mission. Maybe other superheroes find out she's tied up and they have to battle the villains who captured her. They would need to use their unique powers to overcome the obstacles and free her.
Often, characters like Hawkeye might be paired with her. Their long - standing friendship in the original Marvel universe could translate into an interesting dynamic in the fanfiction. He could be someone who helps her adjust to her new form, or they could go on adventures together with her new - found size being an advantage.
Black Widow's comic relationships are quite diverse. She doesn't really 'end up' with a specific person. Her character development is centered around her skills and missions rather than a permanent romance.