Demonic fire

your demonic blood you can control flame 

your powers form as a flaming sword 

Level 3: Demonic flame sword

Your main demonic power comes in the form of a fire sword
As a no action you can summon your fire sword
Deals 1d12 fire damage turns to 2d12 at 7th level and 3d12 at 15th level

Level 3: Demonic flames

you can uses your demonic blood to throw fire out of your hands
as a bonus action you can throw fire at 30ft
deals 1d6 fire damage turns to 2d6 at 7th level and 3d6 at 10th level

Level 7: Demon dash

you can teleport 30ft to a enemy as a bonus action
turns to 60ft at 10th level

Level 10: Demon form

your demonic blood consumes you giving you more power
you get 15ft extra flying speed
you get 1d6 extra ac
your attacks deal 2d8 fire damage
also gives you 1d8 extra hp

lasts for 2 rounds turning to 4 rounds at 18th level

has 3 uses

Level 10: Demonic strike

you can briefly turn your hand into a giant claw to smash an enemy
deals 2d10 Bludgeoning damage turns to 3d12 at 18th level
also releses a small explosion that deals 1d8 fire damage to any enemy 10ft to the target

has 3 uses

Level 15: Fire funnel

you can select an enemy 50ft of you and create a mini tornado of fire
enemy must make a dex save of 14 or take 2d12
if the succed they take half damage

has 3 uses

Level 18: Fire storm

your demonic powers create a storm of fire damaging everything in a 50ft range
every enemy within the 50ft range must make a dex save of 14 or takes 6d12 fire damge
if the succed they take half damage

has 1 uses