Ink — Vladimir Duran

The chase is on! There's a demon loose and Rhea's the only one who can catch the monster before it destroys the wizard city. From the outer docks, to the sunken underwater city, to the very heart of the ocean, it's a bone breaking battle and a non-stop chase through a metropolis of wonder and magic. Life and death will come down to the answer to one question. Are you fast enough?

Excerpt:

The scout didn't slow as she ran towards the edge of the rooftop, she sped up. At top speed she leapt over the side.
Calculations and game scenarios ran through Rhea's head in the second it took her to leap. She mapped the arching bridge of pale brown stone, the people on it, the demon's location. The world below was a puzzle to be solved and her target was the centerpiece. In a fraction of an instant she had it analyzed and came up with the best plan.
Tendrils of cobalt blue and green power extended themselves from her spread hands. Her prey, the demon, turned to look up at the sudden spike of power. Too late, the scout had launched her spell. A spreading net of blue and green energy that expanded as it fell toward the fiend.
Through the translucent screen of her spell Rhea caught sight of the demon's face under the rough tarp it had been using as a cloak. A dust colored feminine face with three pairs of horns and blue eyes without sclera. It sneered a smile and blinked out if existence.