You are a creature of shadow, for your innate magic comes from the Shadowfell itself. You might trace your lineage to an entity from that place, or perhaps you were exposed to its fell energy and transformed by it.
The power of shadow magic casts a strange pall over your physical presence. The spark of life that sustains you is muffled, as if it struggles to remain viable against the dark energy that imbues your soul. At your option, you can pick from or roll on the Shadow Sorcerer Quirks table to create a quirk for your character.
1 - You are always icy cold to the touch.
2 - When you are asleep, you don't appear to breathe (though you must still breathe to survive).
3 - You barely bleed, even when badly injured.
4 - Your heart beats once per minute. This event sometimes surprises you.
5 - You have trouble remembering that living creatures and corpses should be treated differently.
6 - You blinked. Once. Last week.
Starting at 1st level, you have darkvision with a range of 120 feet.
When you reach 3rd level in this class, you learn the darkness spell, which doesn't count against your number of sorcerer spells known. In addition, you can cast it by spending 2 sorcery points or by expending a spell slot. If you cast it with sorcery points, you can see through the darkness created by the spell.
Starting at 1st level, your existence in a twilight state between life and death makes you difficult to defeat. When damage reduces you to 0 hit points, you can make a Charisma saving throw (DC 5 + the damage taken). On a success, you instead drop to 1 hit point. You can't use this feature if you are reduced to 0 hit points by radiant damage or by a critical hit.
After the saving throw succeeds, you can't use this feature again until you finish a long rest.
At 6th level, you gain the ability to call forth a howling creature of darkness to harass your foes. As a bonus action, you can spend 3 sorcery points to magically summon a hound of ill omen to target one creature you can see within 120 feet of you. The hound uses the dire wolf's statistics (see the Monster Manual or appendix C in the Player's Handbook), with the following changes:
The hound appears in an unoccupied space of your choice within 30 feet of the target. Roll initiative for the hound. On its turn, it can move only toward its target by the most direct route, and it can use its action only to attack its target. The hound can make opportunity attacks, but only against its target. Additionally, while the hound is within 5 feet of the target, the target has disadvantage on saving throws against any spell you cast. The hound disappears if it is reduced to 0 hit points, if its target is reduced to 0 hit points, or after 5 minutes.
At 14th level, you gain the ability to step from one shadow into another. When you are in dim light or darkness, as a bonus action, you can magically teleport up to 120 feet to an unoccupied space you can see that is also in dim light or darkness.
Starting at 18th level, you can spend 6 sorcery points as a bonus action to magically transform yourself into a shadowy form. In this form, you have resistance to all damage except force and radiant damage, and you can move through other creatures and objects as if they were difficult terrain. You take 5 force damage if you end your turn inside an object.
You remain in this form for 1 minute. It ends early if you are incapacitated, if you die, or if you dismiss it as a bonus action.