Wanting magic in a rules-light system like FAE can be tricky.
The table pretty much has a handle on what characters can physically do, but also want to sometimes have characters engage in some Subtle Arts. Some magic. They want robed wizards and ancient rites.
So you want to be a wizard.
First, obviously, you need a reason for your character to be working their wizardry. A character- or scene- aspect is an excellent example, but you could also use certain kinds of consequence like “cursed” or “tainted by chaos”.
Which implies that first-before-first, the table needs an understanding of how they want magic to work! See if some of the below options appeal.
Magic as a tool
To hurl a blast of fire, make a forceful roll; to Jedi mind trick a guard, sneaky. This relies on a campaign conception of magic that is tool-like, of course, but is exhibited by a direct approach where your character is paying attention to the target and mastery of magic means spells Just Work. This isn’t a great fit for, like, demon summoning or foretelling the future but it’s good for turning invisible or flying.
Just use the rules normally, assuming magic is just another way that characters do things.
Magic as a trade
Insert cost, get effect. Scope a desired effect as negligible (as Tool, above), minor, moderate or severe. Take a consequence of the appropriate level to represent the undertaking. Make a check with a +2/+4/+6 bonus for minor/moderate/severe. This automatically locks certain effects behind a limiter, so you can be more dramatic in terms of what you allow here.
This doesn’t have to be draining or blood sacrifice! The consequence could be “Has performed the Rite of the Black Goat”, after all!
Magic as a art
Some uses of magic are, then, a separate discipline. This use represents approaching a problem by reframing it; rather than trying to attack your foe you might curse them remotely or instead of forging a bond with an object of affection, you might try a love spell.
Create a new conflict or contest against a pseudo-npc, Magic. If you succeed at this contest, the magic will do what you want (and curse your for or encourage love with your object of desire). The magic NPC is appropriate to the working, generally resisting your attempts to overcome and, should it prove victorious, inflicting shifts of stress. It may have stunts or allies; other practitioners are also interacting with Magic at various levels of antagonism, sao what you do can have wide-reaching effects.
Magic… Always has its price!
Magic is inhuman and permanent. The stress from casting will build up over a lifetime (turning the practitioner mad, into a demon, into a pillar of salt). Every inch lost is a permanent and vivid scar that changes the practitioner.
In order to remove a consequence inflicted by magic (whether practitioner or victim), you must change an aspect (more dramatically for more severe consequences) to be more magical in nature.
At a certain point, you may no longer be able to taint aspects. At this point, your character is so thoroughly un-mundane they may have difficulty amongst non-magicals!
Magic calls to magic
When you try to use magic against someone else, their minimum Defend roll is 2 if they have no magical aspects.
Fear leads to anger. Anger leads to hate. Hate leads to suffering.
Magic used to destructive ends is catastrophic and rebounds.
As a sort of campaign-level stunt, when you attack forcefully using magic, you inflict +2 stress. Each attack costs 2 stress, though conceivably someone callous could take a stunt to reduce that cost…
That’s just wrath, too. Presumably envy, lust, gluttony etc also get in on this boost-for-cost arrangement.
This is very similar to boost-for-cost, positing a standard charge for turning to the dark side of the force.
If you just believe
Magic requires a resource from the practitioner beyond energy; it requires hope and faith and spirit and belief. To use magic, practitioners must first create an aspect on themselves which is what they use to cast. The stronger their belief, the more of their power they can bring to bear; in contrast, if they are distracted or demoralized, they cannot use their powers.