Magic
Here, we’re talking about a formalized system of mystic study, like casting spells you learn from a grimoire, and manipulation of spiritual entities such as the demons that the Grail Knights battle. The practice requires dedication, memory, and other specific mental aptitudes. Ghostheart is a classic example of a magic practitioner in this sense.
Adam Amari might take to it, but I feel he’s mistrustful of the general concept based on the people he’s seen using it already.
Charlotte Palmer was the Magus for a time and since has employed a mixture of “native” ghostly abilities, spirit manipulation, and sorcery. Her origin story is that she was designed to be an excellent receptacle for spirits - the core of a powerful new god.
Harry Gale might not have the highest mental aptitude for it, and like Adam may mistrust it based on how he’s seen it used.
Jason Quill and Alycia Chin have the brains and drive to be potent occultists, and have probably seen enough things in their lives to toss off a minor effect under the right circumstances.
Leo Snow is too much of a committed materialist to buy into this kind of nonsense - he might have the brains for it, but absolutely lacks the temperament.
The Marvelous Menagerie
Of anyone, Ninjess might be interested in learning sorcery, as another tool in her arsenal. Whether Atlantis’ trained ninja ever had an opportunity to learn magic or not is unexplored.
Mirage would reject the occult due to her particular origin.
A10’s powers are already semi-mystical in nature, but she doesn’t really engage with that angle - she’s happy enough hitting hard and bouncing bullets. If circumstances changed, she might change her mind.
Menagerie In Action
Emma is happy enough developing her native powers, Nono is too wrapped up in spy shit, SNOWMAN is a younger Leo for our purposes here, and Alex is like Leo in that they’re too committed to a basically materialist, technological mindset. Whether any of them had the brains for magic, none has the temperament.
Menagerie at Midnight
Bodark and Vermillion practice their own particular flavor of magic, endowed by the Primal Shards which make them what they are. Bodark summons the Wolf, a primordial manifestation of fear, while Vermillion’s power is to tell lies so potent that reality itself is fooled.
Manny the Skull likewise is a supernatural being, but doesn’t employ the supernatural as a tool.
Equity has “superpowers” that are really just applications of her connection with her divine patron Palamedes. Her “justice sense”, for example, is just an awareness of how much Palamedes’ divine portfolio asserts itself in a given situation.
Maury Jones is smart, but in a practical, purposeful way. She probably wouldn’t function well as an occultist.
Newmenagerie
Unlike Leo, Aria and Summer are more spiritual and would be willing to engage with magic if they felt compelled. Neither have availed themselves of Charlotte’s growing library of occult tomes, however, as they’re too busy with their own pursuits.
Otto and his creations Big Bill and Mo likewise are too busy perfecting their rescue-robot schtick to find magic of any interest. They generally share Leo’s materialist tendencies but aren’t as committed to them as Leo is.
Menagerie Megaverse
William already wields Excalibur. In addition, both he and Jaycee have a working knowledge of Goetic demons - enough that Jaycee was able to summon a demon during William’s Ascension ceremony.
Nobody wants Jordan or Space Bug anywhere near a spell book.
Keri already has a power of her own, and has enough trouble coming to grips with the prices it’s demanded of her. She probably lacks the scholarly attitude for formal sorcery, and would certainly not be interested in some of its prerequisite sacrifices.
Others
The Menagerie of the Multi-65 parallel universe are mostly magicians of one form or another.