Magic

Just over a century ago magical abilities began to surface in the world.
A vast array of effects are possible, both wonderful and dangerous. These include the ability to heal people's wounds, move objects with the mind, and create intense fire that can cause others terrible harm. 
The source of the energies is not known. But, as is usual among sentient lifeforms, the gaps in knowledge are filled with theories and beliefs, many of the latter relating to myths and religion.
Work investigating the nature of magic was outlawed in many countries at the behest of the most predominant religion, The House of the Seven Divines. Up to that point, such sorts of power were only conferred to Priests of that Order through the Holy Symbols of their gods.
Fortunately, these restrictions are irrelevant in the science city of Agano. Work there led to a theory that some people can draw on energies that exist in the atmosphere - a phenomenon called Tuning. They are capable of manipulating and transforming them into various effects.
Further research led to the ability to identify and measure these energies in the form of waves of varying size.

Manifestation

Magic system. Eg powers given by moon will be effective only when that celestial body is in the sky and more and less potent depending on if it is full, half, etc. could also be effected if covered by cloud at just the wrong moment. Could make some sources / magic very potent and powerful but only “available” for very short periods of time - and this is its limitation / restriction. Other sources are weaker but available for longer. What is THE source of the magical energy - the dragon in Berdix breathing / its breath. This implies a number of these creatures as celestial bodies. Perhaps even some far away constellations also provide energies, so powerful that they still reach Acuthan albeit diluted (but still powerful) by the time they reach it. Only in very rare cases can people use this energy - long lost lines of descendants that now number so few. But their power is great. Good if a number of moons out at the same time as can then have battles. Also pursue the idea that magic using people can be “cured” and the resistance to this as well as the fierce desire of non magic using folk for this cure to be applied to all magic users, and by force if necessary. Cf x-men and of course some may be lie rouge where they want to be cured because they cannot fully control their powers and have hurt or killed by accident or in fits of rage - like Scott and his eyes… but perhaps these powerful folk are also part of the best chance to defeat those who use magic to conquer and subjugate. They must be defeated but this would be like a sacrifice for those who want nothing to do with their own powers.