Your connection to Death gives you incredible resilience to it's grip. Though you're tough to keep down, your body is frail. 

Your hit die is always a D6, regardless of what class or classes you might take. 

In addition, when you are reduced to 0 hit points but not killed outright, you can to drop to 1 hit point instead. Each time you use this feature after the first, you must make a DC 10 Constitution save, and the DC increases by 5, as well as the DC for any death saves you make. When you finish a long rest, the DC for both resets to 10. If you would die as a result of failing a death saving throw, you don't. Instead, you regain 1 hit point, and your Constitution score is permanently reduced by 2. If this feature would reduce your Constitution score to 0, you instead become a mindless undead.

Darkness holds no secrets, and spirits can't hide from your cursed eyes. You can see normally in non-magical darkness up to 60 feet. You can also see into the Ethereal plane up to 30 feet, thanks to your natural, or unnatural as the case may be, connection to the spirits of the dead. 

Death takes more than it gives, but when it does give, it gives gravely. You are void of most emotion, maybe even a soul, an unliving body, a breathing corpse. 

You don't age, and are immune to magical aging. You are immune to being charmed, frightened, and poisoned. You no longer need to sleep, and can't be magically put to sleep. However, you also aren't affected by most magical healing, nor can you be resurrected if you die.

You still need 8 hours of light activity to gain the benefits of a long rest. 

You are humanoid, celestial, and undead. 

You are Small or Medium (your choice).

Your base walking speed is 30 feet.

One Ability Score of your choice increases by 2.

You can speak, read, and write Common and one other language that you and your DM agree is appropriate for your character.