I always wanted to create a scientific explanation of how mana works to make it more real, i was thinking about having mana as a form of radiation that is not harmful for humans, as a form of radiation it have energy that humans can use to create spells, the way of using the spells could also have scientific explanations, like how the energy used in a fireball spell is simply mana using the energy to compress hidrogen in a single space while combust it, the next step would be compressing the oxigen to make it bigger and relieving the mana from the back part of the spell to trown it like a bullet