What is the fine-grained topic of the following text: Where Loyalty Lies features 12 unique characters, including new versions of existing characters and exciting new characters like The Mountain that Rides, Ser Gregor Clegane, one of the most wicked and fearsome villains from George R. R. Martinâ€™s A Song of Ice and Fire. Only return the topic.
Character introductions in the "Where Loyalty Lies" series from George R.R. Martin's "A Song of Ice and Fire".