Sorcerous Origins: Inner Darkness

Your accursed deeds (or your ancestors) have unlocked a terrible power that provides your innate connection to magic. Perhaps you were exposed to a great source of negative energy, or sought knowledge that was not meant to be known by mortals.
Some "dark sorcerers" had their curse visited upon them by others, but use their power to return a twisted vengeance on those who've wronged them. Still others fight against their dark desires, and seek to use their powers for good... even if their methods call much into question.
Dark Sorcerers, sometimes called "slashers," are driven to symbolism and iconography. They favor specific weapons and clothing with particular patterns. Some wear masks, or dress as odd mockeries of a specific trade or profession. Other slashers hum a repetitive tune, or twist their words into bizarre rhymes. These strange trappings serve to haunt the targets of their wrath, and become the seeds of local legends, or scary tales told to frighten children.

Signature Weapon

You gain proficiency in a weapon of your choice that does not have the "heavy" property. While wielding this weapon and nothing else (including a shield). you gain +2 damage to melee attacks. Your signature weapon counts as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.
You may use your signature weapon as a spellcasting focus.

Prey Sense

The evil inside you drives you a stalk and hunt a specific target.
Starting at 1st level, as a bonus action, you may cast the spell Hunter's Mark as if using the highest level spell slot available at your level (without expending the spell slot.)
This spell must target a creature you have dealt damage to within the past day. You may use this ability a number of times equal to your charisma modifier (minimum 1.)
You regain all expended uses of this ability after a long rest.

Unstoppable

At 6th level, you gain additional abilities against targets of your Prey Sense:
As long as you and your marked target are on the same plane of existence, you are magically aware of the general direction and distance of your target, even if they are invisible or magically prevented from leaving tracks.
While traveling toward your marked target, you are immune to fatigue and do not gain exhaustions levels.
Bludgeoning, Slashing and Piercing damage dealt to you by your target is reduced by 3.

They Always Come Back

Starting at 6th level, if an attack would reduce your hit points to 0 or fewer you may instead spend a sorcery point to be rendered prone, and have that attack reduce you to 1 hit point. To all others, you appear dead (as if affected by Feign Death.)
This illusion persists until you choose to move or take any action. Other creature can move or manipulate your body without ending this effect. If you spend a full round under this disguise without taking an action, you may spend hit dice to heal ( as if taking a short rest) without ending the illusion.

Pervert Gravity

Starting at 14th level, whenever you spend a sorcery point for any reason, you gain the effects of the spell Spider Climb until the end of your next turn.
Furthermore, you learn the cantrip Thaumaturgy. You may cast this as a free action once per turn.

Horrific Teleport

Starting at 18th level, as a bonus action on your turn, you may spend a sorcery point to teleport to a space adjacent to the target of your Prey Sense.
You choose the space where you arrive. If your target could not see you when you initiated the teleport, it must make a wisdom saving throw against your spell save DC. On a failed save, the creature is frightened of you until the end of your next turn.