Demonic bloodline

Raw demonic power runs in your veins. Urges for death and destruction are always in the back of your mind whispering.

Language of the damned

You learn to speak read and write abyssal. If you already know abyssal you may pick an additional language.

Demonic change

Your skin hardens giving you a AC of 13 + Dex.

This increases to 14 at 6th level and you gain fire resistance 

15 at 14th level and gain gain necrotic resistance 

16 at 18th level and once per short rest when hit by a Fire or Necrotic attack you instead absorb the damage healing for halve the damage.

Hellflame

At 6th level when you cast a Fire spell add 1d6 Necrotic damage 

At 14th level when you cast necrotic spells add 1d6 fire

At 18th level whenever you cast a fire or necrotic spell deal an additional 2d8 fire and necrotic damage.

Souleater

At 14th level when you kill a target you replenish one sorcery point

At 18th level when you kill a target you replenish one sorcery point and heal 1d6+con.

Thane of hell

At 18th level twice per long rest you can change a a 200ft area into the fiery bowels of hell . Any creature you see and choose are immune to the following effects. The area remains for 6 turns

3d8 fire damage per turn

2d8 necrotic damage per turn

Whole area is difficult terrain

Must pass a DC 18 wisdom check to cast radiant spells