Soul Sacrifice

Soul Sacrifice

Soul Sacrifice is a feat unlocked by the Warlock at 1st level. It may be used by Fiend warlocks especially. Soul Sacrifice allows the Warlock to send the soul of a victim to their Patron. To do that, they need to draw a Transmutation Circle. You can draw multiple circles in each other.

Transmutation Circles

The Transmutation circle can be drawn with one of the following Materials, which make a difference in how much Soul energy they can hold and thus keep the circle from collapsing. Materials are listed here, the DM may add others too.

• Blood (1 Soul Energy Units/ Circle)
• Chalk (2 Soul Energy Units/ Circle)
• Iron [dust] (4 Soul Energy Units/ Circle)
• Silver [dust] (8 Soul Energy Units/ Circle)
• (Un-)Holy Water (4 Soul Energy Units/ Circle)
• (Un-)Holy Silver (12 Soul Energy Units/ Circle)

To finally activate the circle(s), you'll need

• The blood (or any organic matter) of the sacrifices
• The blood of the patron (or a subordinate)
• A catalyst

Soul Energy Units

Soul Energy Units is a unit created to exactly determine the power a soul holds. To calculate the power a soul holds, you need to look for two things.

1. The level or challenge rating of the sacrificed soul. It's worth one soul power every two levels or challenge rating.
2. The Intelligence. Use the modifier as the soul energy it provides 1 for 1.

Catalyst

A catalyst is an item given to you by your patron. It allows you to link the Transmutation circle to them. It also multiplies the soul power and grants additional benefits. You get better catalysts as you level up. 

Special bonusses:

1 - You can see souls

2 - Resistance to a specific damage type that matches your patron

3 - Resistance to magic

Note: That's all just examples.

Your DM may decide what kind of bonusses you get by sacrificing souls to your patron.