I am not sure the details of the magical system are apt to be the interesting bits.
What does the world look like? I think that depends more on how people react, rather than what they can engineer to do with newfound power. How do the world's religions react? How does humanity deal with its racist tendencies, its fears of replacement, and its outright ignorance? How do governments react to new threats that had clearly completely gone without notice... for centuries?
Those reactions will shape the world more than the details of exactly how magic works. IMHO.
What does the world look like? I think that depends more on how people react, rather than what they can engineer to do with newfound power. How do the world's religions react? How does humanity deal with its racist tendencies, its fears of replacement, and its outright ignorance? How do governments react to new threats that had clearly completely gone without notice... for centuries?
Those reactions will shape the world more than the details of exactly how magic works. IMHO.