Soulweaver

In the realm of shadows, you are a Soulweaver, a master of the macabre and the ethereal. As you stride through the darkness, your blade, empowered by the harvested souls of the departed, cuts through resistance and pierces the very essence of your foes. With a whispered invocation, the Soulharvest envelops you, bestowing an otherworldly speed and marking any nearby adversaries for a dance with death. Your familiar, a spectral raven or crow, serves as a faithful companion, aiding in marking targets and weaving the threads of fate. Together, you embody the convergence of necromantic prowess and spectral grace, an enigmatic force feared by all who dwell in the shadows.

Reaper familiar

Starting at 3rd level as part of a long rest you can cast find familiar without material components but you can only summon a raven or crow. Additionally if the raven takes damage you can choose to suffer the damage instead.

Marked for death

The first time you successfully hit a target as part of the attack action you can mark them for death. When this happens your familiar will spend their action following the target to the best of it's abilities. Provided your familiar is within 30ft of the target you crit on a roll of 19-20 against them. Every turn that the target is marked they suffer phycic damage equal to your level at the beginning of your turn. This marking lasts for one minute or until they die or you or your familiar are incapacitated. While this effect is active you suffer disadvantage against any target that isn't marked.

Can use once per short rest. At 11th level you can use this feature twice per short rest 

Soul cleave

When successfully landing a melee attack, you have the option to spend hit dice equal to your proficiency modifier, adding 1d10 necrotic damage. If the target is marked, they must make a Wisdom saving throw (DC 8 + your proficiency modifier + the number of hit dice expended). On a failure, they experience a haunting vision of death, becoming frightened for one minute or until struck by an attack, during which their movement speed is reduced to 0.

Can use once per short rest

Familiar Fusion

As a bonus action you can combine with your familiar, you gain their movement speed and senses and the benefit of the disengage action but can't take actions unless you end the transformation (no action required)

Can use an amount of times equal to your prof mod

Soulharvest

Upon killing a target, use your reaction to absorb their soul, gaining temp HP (level + double prof mod). Also, deal an extra d10 necrotic damage to marked foes. Once per turn

Soulweave Ascendance

Channeling the essence of the departed, unleash the Soulharvest with a bonus action. Infuse your strikes with 1d10 extra necrotic power, transcending resistance and immunity. Ascend with a floating speed of 60ft. As you activate this ethereal force, a dark aura extends within 10ft, automatically marking a target under marked for death when this feature first activates

Can use once per long rest