Devin Butler

A soldier engineered as a military magic program's control subject — no natural mana pathway, a manufactured lattice instead — is publicly disgraced by design so he can guard the heiress he saved from a bombing. She solves him one fifth of the way in and spends the rest of the season committing lawful-looking crimes to keep him, because Earth's statute says a capacity above the line must be registered to an owner, and because what he actually is, a regulator, is what a blood-drinking empire crossed a galaxy to stop needing.