Witch hunters

This world's history is not the history you know.
Technological and cultural advancements have happened centuries ahead of schedule due to the advent of mysterious abilities dubbed 'blessings'. Those who use these powers for good are called 'agents', guardians of the world who fight against the evil 'psykers'.
For a time peace reigned, while yes the psykers attempted to destroy that peace they were always beat back by the agents, that was until the witch came.
This is the tale of three rulers who sought to hunt the witch and bring an end to her terror across the world.