Liquidator in the Service of the Empire

In our world, evil exists. It seeps into everything and destroys the balance. But no one wants to fight it. Worse— the strongest clans are fighting for the right to bring it into their ranks. Their… outsiders from another world take over people’s bodies and live among us. They possess immense magical power and completely lack any principles.
But the heir of the Volkov family will put an end to it! After all, for that there is everything needed, including a one-hundred-percent guarantee that no creature will be able to take over him..