Black Soul Trap

This spell snatches the soul of a humanoid as it dies and traps it inside the empty black soul gem you use for the material component. A stolen soul remains inside the black soul gem until it is used or until you destroy the gem, which ends the spell. While you have a soul inside the gem, you can exploit it in any of the ways described below. You can use a trapped soul up to five times. Once you exploit a soul for the fith time, the gem is destroyed, and the spell ends. While a soul is trapped, the dead humanoid it came from can’t be revived. Also if the soul is exploited a fith time or the soul gem is used in enchanting, that humaniods soul is sent to the soul cairn and then cannot be resurrected or raised by normal means.
The humanoid soul makes a wisdom saving throw against your spell save DC with advantage. If it passes the spell fails and the spell slot is wasted. If it fails it is captured.
Steal Life. You can use a bonus action to drain vigor from the soul and regain 2d8 hit points.
Query Soul. You ask the soul a question (no action required) and receive a brief telepathic answer, which you can understand regardless of the language used. The soul knows only what it knew in life, but it must answer you truthfully and to the best of its ability. The answer is no more than a sentence or two and might be cryptic.
Borrow Experience. You can use a bonus action to bolster yourself with the soul’s life experience, making your next attack roll, ability check, or saving throw with advantage. If you don’t use this benefit before the start of your next turn, it is lost.
Eyes of the Dead. You can use an action to name a place the humanoid saw in life, which creates an invisible sensor somewhere in that place if it is on the plane of existence you’re currently on. The sensor remains for as long as you concentrate, up to 10 minutes (as if you were concentrating on a spell). You receive visual and auditory information from the sensor as if you were in its space using your senses.
You can also use the filled black soul gem for any of the normal uses of soul gems. On first being trapped, any humanoid soul trapped inside will count as Grand. However on be exploited in any of the ways listed above, the soul degrades by one level. Becoming Greater after first use, Common after second, ect.
A degraded soul can still be released if the soul gem is destroyed before the fifth exploitation. However that soul will be permenently degraded and partly tied to the soul carin, meaning that if that soul is raised or resurrected it will suffer a permenent -1 penalty to all attack rolls, saving throws, and ability checks for each time it was exploited, up to -4. Additionally if that soul is captured in a black soul gem again it will still be as degraded as it was on being released. Only a Wish spell can end this effect and restore the soul to Grand.
A creature that can see the sensor (such as one using see invisibility or truesight) sees a translucent image of the tormented humanoid whose soul you caged.

Related Discipline

Warlock, Wizard

Related School

Reanimation

Effect Duration

Until dispelled

Effect Casting Time

1 reaction, which you take when a humanoid you can see within 60 feet of you dies

Range

60 feet

Level

6th-level