Witch Patron

Source: Hexbound

Witches need a mentor to teach them witchcraft. Warlocks need a patron to grant them their powers. As a Witch Patron warlock, your mentor and your patron are one and the same. An incredibly powerful witch taught you witchcraft, and through your covenant they also became both your mentor and your patron. Your magic stems both from the summoning of spirits and from your mentor themselves. You are able to tap into your patron’s immense source of magic, so long as they agree with your actions.
Under the watchful eye of your familiar, your patron sees your every move. Whether this is to protect you from harm or to ensure you carry on their evil deeds depends on the mentor and patron you chose. Your training under an immensely powerful witch has taught you the importance and strength that lies in belonging to a coven; a powerful coterie of magic users that enhance each other’s magical abilities. You know that there’s strength in numbers, and with both your coven and your familiar at your side, there’s little in this plane or any other that can oppose you.

Witchmark

Witch Warlocks have the most diversity in their witchmarks, since they depend solely on their patron and mentor. Some noble witch mentors use their family’s coat of arms as their witchmark, while other patron mentors choose a witchmark in the shape of a ring around the finger of their pupil to illustrate their bond. The most common motif is chains snaking around the body of the pupil symbolizing the unbreakable covenant between the patron mentor and the student.

Coven Bond

At 10th level, your mastery over witchcraft has grown, and so has your coven. Up to three willing creatures with whom you share a close bond and who are able to cast spells can now be part of your coven. Their magic is further empowered as your bonds grow stronger.
When all members of the coven are within 50 feet of each other:

• Members of the coven cannot be charmed
  or frightened.
• Members of the coven have advantage on Charisma saving throws.
• Members of the coven do not receive any damage caused by a spell cast by another member of the coven as long as that spell has an area of effect. For example, a fireball cast by one member of the coven does not affect the other members. Members of the coven do not need to make saving throws when entering the area of effect of another member’s spell if the saving throw is used to determine how much damage they would take. Other effects, such as blindness or deafness, are not negated and members of the coven need to make the appropriate saving throws if in the spell’s area of effect.