The 'I am the sole immortal novel' could potentially center around a character who discovers their immortality and feels isolated because of it. They may be on a quest to either find others like them or to understand the reason for their immortality. The story could delve into the moral and ethical dilemmas they face. For example, do they use their immortality to gain power over mortals? Or do they try to hide their immortality to avoid being seen as a freak? There could be a lot of internal conflict within the character as they navigate their unique existence.