You are the one that hunts down rouge spell casters, that uses magic to make horrid monsters or hags that steal children or cruse the common folk. You are what stands between terrors of magic and the normal people of the world. 

Oil Crafter

You gain proficiency with either alchemist's supplies or an herbalism kit.
You can also as a bonus action coat one of your weapons in oil that does 1d4 element damage of your choice between acid, cold, fire, lightning, or thunder. These benefits last for one minute and have a number used equal to your proficiency bonus. You regain all uses of this ability once you have completed a short or long rest.

Know thy Enemy

Your years of hunting down rouge spellcasters have taught you where to look and how to find those that have a bounty on their head. You have an advantage on survival checks to track spellcasters and knowledge checks to recall information on them.
In addition, you gain proficiency in one of the following skills of your choice: Investigation, Insight, or Survival.

Spell Disruption

You gain the ability to fight against the magic your enemy is throwing at you, you have the ability to cast Counterspell and Dispell Magic a number of times equal to your proficiency bonus. You regain all uses of this ability once you have completed a long rest. The ability score used when needing to roll for counterspell or dispel magic will either be Int. or Wis. was chosen by the player.

Iron Mind

If you start your turn charmed or frightened, you can use of your Spell Disruption in order to end the status effect.

Magical Evasion

Your tireless battle with witches has granted you the ability to have a better defense against their spells, you have an advantage on saving throws against spells.

Earthly Protection

You are always under the effects of a Protection from Evil and Good spell, also you have the ability to cast dispel evil and good once per day. You regain all uses once you complete a long rest.