More than Magic by Cheshirkas (Patreon)

Despite having less potent quintessence and rather average spirit wells, cubi like Monette are powerful spellcasters. This is because of their abnormally large bucket capacity, natural  attunement with the flow on all levels, allowing for expert manipulations of the aetheric energies of the world . The average cubi's 'Arete' is at least silver level from birth, and they only grow more powerful.

Some, like Monette, have incredible 'Source Retention' and wordsmithing abilities making them expert spellcasters, along with their natural racial abilities. Her knowledge alone would make Monette a Gold Level awoken, but given her more potent than average quintessence, as well as years of knowledge in the Arcane Artes, Monette was at least a Platinum level threat, and that is before she is empowered through feeding.

With part of her powers sealed, she's merely at the level of a powerful wizard. But unbound, she would be a match for any High Wizard in the land of Theria, and with enough stolen essence from her thralls and victims, even and Archmage would have hard time taking down the salacious succubus.

Thankfully such boosts in her power are not permanent, for if she brought all of this power to bear against the foolish warrior who sought to beat her at her own game, perhaps even the Crimson Raven would have fallen to her hellacious charms.