In this world, the most powerful thing was magic. The top-level battles were all decided by magic. There was nothing that strong enough magic couldn't solve. If there was, it meant there weren't enough people. Just add more people, those with strong magic power.
A powerful spellcaster needed an immense amount of knowledge and abundant magic power. These both required time. So, longevity was power, the longer you lived, the more meals you ate.
The top of the food chain was always occupied by immortal races. However, this didn't mean that being an immortal race necessarily made you powerful.
The strength among immortal races also varied greatly.
