An otherworldly force of nature invoked in the material plane by those who can pull energy from the mystical plane.
Explanation and Access
Currently, the only people who can access magic are those who have directly taken in energy pulled from portals to the mystical plane. These portals are currently controlled by The Welldrinker Cult, who have used this claim to empower their membership.
Some spells and rituals established before the magical rebirth would now carry more power, so existing magical studies can prove useful, but for many spells, there would be trial and error.
Unlike mutation, while magic gives people access to power, it is not innate. All spells have either hand motions or materials and rituals required to complete. Even a Snapping spell, while instinctively known, requires some kind of ritual or focus to perform.
Adapted fields have no impact on magic whatsoever - they evolved to negate the X-Gene.
Limitations of Magic
No outright death magic, No altering space and time, No limitless resurrection, Abilities should be weaker than a comparable mutation (ex. A magical fireball should be a burst of fire compared to the raging inferno of a mutant). If something was created by magic, it still works as if it were created non-magically, so you fireproof mutant is still immune to a magical fireball. Magical items and potions can be created, but they lose power and efficacy over time and must continually be recharged (as will any long-lasting spell).
More limits can be added as they become necessary or obvious.
Schools of Magic
Warding and altering magic that can “charm” or even "hex" a space, person, or object that alter it without changing its essential nature.
Magic that summons or calls something to a location. This also allows for the creation of objects, and potentially even animation, but both require magical focus to maintain.
A more ritual-heavy school focused on revealing knowledge, whether that’s glimpsing potential futures, gaining hints toward secrets around you, and revealing what might be concealed.
Channeling the raw magical energies of the mystic realm and converting it into new destructive or beneficial energy, from a soothing wave of healing to a burst of flame or a violent burst of pure arcane energy.
The ability to alter perceptions, masking reality to those who interact with your illusions, simulating sensory interactions like appearance, scent, or texture.
Magic focused on the body and life and the manipulation of either. This can alter flesh, mend wounds, and at high enough levels, tamper with genetics.
Completely transforming a person into an animal or other inhuman creature is beyond the ability of any Somation Mystic except for a Supreme.
There are several different ways to increase the potency of a spell or other manifestation of magic. The more powerful the spell and the higher level it is, the more energy it will take to cast it and any verbal or material components will likely become more complicated as well. More powerful spells will also tend to take more time to cast.
To offset the amount of power it takes to perform such spells and therefore reduce chances of burning yourself out from conducting all those energies, a Mystic might consider linking their power with other Mystics or even utilize a Mutant's aid if they can provide the right type of power or materials.
The largest and most powerful/complicated rituals are likely impossible to do without multiple Mystics working together. Multiple Mystics coordinating their power (and knowledge) also reduces the chances of losing control of the spell or any negative consequences occurring (such as magical backlash in the form of Wild Magic).
Casual magic is the most basic type of magic. It's so basic that it doesn't require a user to actively channel power from the mystical plane. Instead, casual magic uses up ambient magical energy that is best described as having "leaked" from the various ley lines and portals that the Welldrinkers have returned to being. This means that anyone (including Humans, Adapteds, and Mutants) can learn and use casual magic, since it does not require genetics that are compatible with conducting mystical energy. However, casual magic tends to be very weak in effect and if enough of it is used in an area, it will use up all the ambient magical energy floating around. At that point, only a Mystic able to channel magic directly through themselves from the mystical plane will be able to perform magic.
Additionally, casual magic is rather intuitive for Mystics, typically not requiring much study or practice at all (since they're capable of far greater feats of magic). For non-Mystics, weeks of dedicated study and practice are required to perform the most basic of spells, such as lighting a candle or temporarily changing the color of something.
For examples of Casual Magic, see the chart of Arcana Classes.