This Is Definitely Not a Proper Succubus [Western Fantasy]

A fairly serious (?) main plot blurb:

To save his country, a prince burdened by a blood feud stakes everything on summoning a genuine ancient succubus. From then on, Shaflay becomes his mentor, companion, stepmother, closest confidante, and most caustic enemy: the first card in his quest for revenge that he can truly trust.

The good news is that the succubus really is dependable. The bad news is that the way she proves it, and the way she helps him reclaim his kingdom, are just a little... unusual.

Shaflay: “Of course I have to use my own methods to bring others on board. You understand, right? I'm a respectable succubus, after all.”

Helios: “Mm.”

Shaflay: “...You do understand what I mean, right?”

The chosen savior, the great White Knight, the uncrowned tyrant, Helios lowers his eyes and toys with her slender fingers, then smiles serenely and nods. “Mm.”

The heroine is entirely nonhuman. The author has a thing for mature older-sister types, and she is perfectly comfortable with the traits of her species.

A self-indulgent Western fantasy. The main plot is an adventure to reclaim a kingdom and explore the map. I don't know why I suddenly really wanted to write it, but I did.

The comments section is open to free discussion, but I won't accept extreme moral condemnation or nitpicky, word-policing scrutiny. It's a pure wish-fulfillment Mary Sue story, so please don't make a big deal out of it.

A shameless, self-indulgent Mary Sue story, with a universally adored heroine.

Theme: Love should celebrate life itself, not resist its passing.