"That's because the root cause of our spells is our own mana and it does us no harm. The effects, instead are produced when the spells interact with the external world energy. They are like the ripples produced by a stone thrown into a lake.
"We have control over the distance the stone travels and the strength with which it lands, but not over the ripples that originate from the impact. Let me give you another example."
Lith raised his right hand, producing such heat that soon everyone had trouble breathing, he included. The same happened when he caused a frost wave that made his teeth clatter.
"See? In both cases, my body is unaffected by the change in temperature that fire and water magic produce but the same doesn't apply to the effect they cause in the environment around me. Any questions?" He asked.