Witch Hunter
Witch Hunters are humans who are employed by practitioners to kill others or enforce the peace.
Advantages & Disadvantages
Being a normal person as opposed to a practitioner affords certain advantages, as Others cannot freely act upon them to a limitation. They can lie, and are freely allowed to invade demesnes without reservation because they aren't bound by the same rules as those who practice.
Their downside is that they are only human and they knew stuff, and it was hard to leave all that behind and live an ordinary life. Practitioners could very well be unhappy or unsettled by the appearance of the twins in their town. Lords or local powers could seek to control them, even abuse them.