Why is the immortal always on my younger brother's horse when there's no horse?

This question involved the concepts of immortals, immortals, and monsters in the novel. Under normal circumstances, immortals referred to people who had achieved success in cultivation and obtained extraordinary abilities through cultivation, allowing them to control the power of nature. Celestial beings referred to creatures with special abilities such as divine beasts and feys. In novels, immortals and demons were sometimes mixed up, and some creatures with special abilities were also called immortals. The reason why immortals were always on horses was probably because horses were usually described as having low-level spiritual power and abilities, which were usually needed by immortals and demons. Therefore, immortals would often choose their younger brothers as their subordinates to help them complete missions and improve their strength through their abilities and spiritual power.