Vengeance by Niall Teasdale

Ceridwyn Brent has been through a lot in the past few years. She’s been kidnapped, assaulted, brainwashed, used to summon an army across dimensions, walked across an alien world to rescue her lover, and had to embody an ancient war goddess to save a world… A bit of normality would seem in order.

But when you’re the most powerful sorceress on the planet, even if very few people know that, and one of the best magical theoreticians in the world, and you have an entire demonic realm to run, normal is not the same as it is for everyone else.