They could be students in the same school. Gil might be good at math and helps Gail with her studies, while Gail is excellent in art and inspires Gil to be more creative in his projects.
In a fanfiction scenario, Viggo might kidnap Hiccup out of jealousy. Hiccup has a special bond with Toothless, a very rare and powerful dragon. Viggo, who has always been obsessed with dragons, may be envious of Hiccup's connection. He kidnaps Hiccup to try and take Toothless for himself. He might think that by having Hiccup in his control, he can make Toothless obey him. He could also use Hiccup as a bargaining chip to get more dragons from Berk.
Well, Hiccup is very resourceful. He could use the environment around him to his advantage. If he is locked in a place, he might find a weak spot in the structure, like a loose board or a hole in the wall. And he could call for Toothless secretly. Toothless, being highly intelligent, could find Hiccup and rescue him. Also, Hiccup could befriend some of Viggo's minions and convince them to help him escape.
I don't know of a 'Free Gil Brewer'. It might be a unique name that is associated with a particular story, place or activity. Without more context, it's difficult to say who this person is.
One idea could be that Harry and Gil go on a treasure hunt that was hinted at in Descendants 2 but never fully explored. They could encounter new magical creatures and face challenges together, strengthening their bond as friends.
Gil and Harry Hook are often interesting characters in fanfiction. Their complex personalities can be explored in different ways. Some fanfictions might focus on their friendship, showing how they support each other in the rough world of Neverland. Others could delve into their rivalry, perhaps competing for the same goal or the attention of a certain character.
Gil Cisneros could have a variety of top stories. Maybe his rise in the political arena is a significant one. He might have stories about his efforts in promoting education or certain social causes. Another possibility could be stories regarding his interactions with constituents and how he made an impact on their lives.
In many fanfictions where Gil gets kidnapped, it could be for various reasons. Maybe it's by a rival group who wants to use him as a bargaining chip against his friends. For example, in some stories, Uma's crew might be targeted because they are seen as a threat in the Isle of the Lost. Gil, being a part of that crew, gets kidnapped. Writers often use this plot device to create drama and show the loyalty and courage of the other characters as they try to rescue him.