Without having read 'The House of Dreams Graphic Novel', we can only speculate. It could be that the main character is a dreamer, someone who has a special connection to the House of Dreams. This character might be on a journey to unlock the secrets of the house. There could be other characters like a caretaker of the house, who has a lot of knowledge about its history and workings. And there might be other dreamers or lost souls who the main character meets along the way. These characters would all play important roles in the story, with their own motives and backstories that are gradually revealed as the graphic novel progresses.
Since we don't have much information about 'The House of Dreams Graphic Novel', it's hard to say for sure. But often in such stories, there is a central character who drives the plot forward. This character might be someone who has been drawn to the house for a particular reason, like a lost memory or a sense of purpose. There could also be supporting characters such as friends or family members of the main character. They might help or hinder the main character's exploration of the house. There could be some magical or supernatural characters as well, depending on the nature of the story in the graphic novel.