Pact of the Soul

As an action you can partly transform into your Patron, whose soul is sealed inside of you. The transformation gives you abilities specific to your patron and lasts 3 rounds. The number of transformations per day is 1 for levels 1 to 10, 2 for levels 11 to 19 and 3 for level 20. The transformation is forcefully activated when you are frightened.

The Archfey- Your transformation grants you immense magic. While transformed, your spells ignore magic resistances and immunity.

The Fiend- While transformed you get incredible physical attributes. Your physical attack rolls ignore damage resistances and immunities.

The Great Old One- When you transform you gain the power to read the opponent's movement by hearing their thoughts. While the transformation lasts every attack roll against you has disadvantage.

The Undying- Your transformation gives you the opportunity to steal life energy. While you're transformed, you take half the damage your exposed to and the person who made the attack also takes damage, the same amount as you do.

The Celestial- You gain the ability to fly swiftly in the air. In the transformed form you have flying speed of 100, but you can't walk.

The Hexblade- You and your weapon become one. When making an attack, you don't need to roll to see if you hit the opponent, it's a sure-fire.