Elves

They're allergic to change, literally. Their age is accelerated by new experiences, as their bodies react to the accumulation of willed energy negatively. A typical elven adventurer will live roughly the same age as a human, but an elf who lives a stagnant life will live for a solid thousand or so years.

Elves are often the definition of practising a single stroke a thousand times. They are the masters of mass production, of perfecting a single strategy in warfare, it is their greatest strength and biggest curse.