To make a character consistent, or to create a completely self-imagined character that runs parallel in a world like that of The Lord of The Rings, it's important to know a bit about the different types of fantasy. Here's an overview:
High Fantasy
A genre of speculative fiction set in an entirely fictional world, often with its own unique history, mythology, and rules. It is characterized by its epic scale, richly developed settings, and a strong emphasis on magic, mythical creatures, and heroic quests. In High Fantasy, the world itself becomes a central element. Examples of High Fantasy are the 'Lord of the Rings' trilogy by J.R.R. Tolkien and "A Song of Ice and Fire" series by George R.R. Martin.
Low Fantasy
Unlike high fantasy, low fantasy takes place in a world very similar to our own world. However, it does contain supernatural elements or magic that affect the story. A well-known example of low fantasy is the "Harry Potter" series by J.K. Rowling, although it also contains characteristics of High Fantasy.
Urban Fantasy
Urban fantasy takes place in modern urban environments and combines supernatural elements, such as magic, vampires, werewolves or other mythological creatures, with contemporary setting and characters. A well-known example of urban fantasy is Jim Butcher's "Dresden Files" series.
Dark Fantasy
Dark fantasy is a subgenre characterized by a dark and sometimes grim atmosphere. It often includes horror or gothic elements and often features complex and morally gray characters. A well-known example of dark fantasy is Joe Abercrombie's "The First Law" trilogy.
Historical Fantasy
This genre combines elements of fantasy with historical setting. It places supernatural elements, such as magic or mythical creatures, in a specific historical period. An example of historical fantasy is Diana Gabaldon's "Outlander" series, which mixes time travel and Scottish folklore with the Scottish Highlands in the 18th century.
Science Fantasy
Science fantasy mixes science fiction elements with fantasy elements. It combines technology, space or futuristic concepts with magic, myth or supernatural powers. A well-known example of science fantasy is Frank Herbert's "Dune" series, in which a futuristic society is combined with mystical elements.
Almost all fictional stories and games are based on the above forms of fantasy.