Devouring

You take a creature willing or unwilling and place them within a circle drawn on the ground with chalk, eight candles must be placed and burning around the chalk circle with magical runes wrapping around the border of the circle.

The target must be unconscious from an Eldritch Blast cast by "The Devouring" subclass of warlock. Through out the ritual the warlock chants magical inactions with his hand placed upon the creatures head. At the end of the ritual the soul and magical essence is siphoned into the warlock and empowers him with the creatures magical abilities.

You get one cast per warlock level divided by 2 rounded up of the following spells based on the caster you devoured, these spells do not come back after a short or long rest and are lost if the [Tooltip Not Found] is used again before the charges are gone.

Cleric
Cure Wounds

Warlock
Hex

Wizard
Magic Missile

Sorcerer
Chromatic Orb