Thailand Versus Taiwan III
Xinthri is actually using a unique source of energy that is called Prana. It is a branch of life force or life energy that draws from the excess life around him. The garuda race also has a special core that can store Prana passively as it is built up.
Mana and Prana are both similar, but their essence is very different. Mana is also a life source while Prana is also a life source, yet they are both different. Mana is life source that is used to induce change in Phenomena as it could become any element that the caster can use.
It is also the reason why using all of a person's mana could make them go into shock or Mana Overload. The person that used all of his mana will not die despite it being a life force because the body has something like a preservation mode. The body will never let itself get drained of mana completely as mana is also the thing that binds the body and the soul.