Fel Sorceror

As a Fel sorceror, you utilise power inherited from demons. When demons use this power, it simply takes the form of green gas and fire that provides them limitless power. When you use it, it burns through you in strange coloured blood - The stronger the power you use, the hotter it burns.

Your innate magic comes from a demon's power that was ingested by you or one of your ancestors, whether it was chosen or forced. Demons have a practice of making their prisoners kneel and pushing small amounts of raw fel energy down their throats, slowly burning a path down as it reaches their stomach. A strong-willed individual can ingest this energy into their body, but to do so requires being able to ignore the feeling of pure inferno burning your flesh from the inside. 

Demonic Ancestry

Starting at 1st level when you choose this origin, whenever you use a sorcery point, take 1 fire damage for each point used that ignores immunities and temporary hit points, and gain a number of Fel Counters equal to the damage you took. A fel counter can be used whenever you hit with a damaging spell to deal +2 extra fire damage per counter used. If you end your turn while you still have any Fel Counters, take 1 fire damage. You may spend 1 minute converting your Fel Counters into temporary hit points. Each Fel Counter is worth 2.5 hit points rounded down when you convert them. Fel Counters are reset to 0 any time you take a short or long rest.

Astounding Courage

The iron will you or your ancestor showed upon receiving your power is reflected in one of the benefits the power gives you. Gain 1 additional maximum hit point, and gain 1 more whenever you receive a level in this class.

Fel Reinforcement

Upon reaching 6th level, you have learned to utilise the power within you to strengthen yourself outside of casting spells. As an action, you can spend a Fel Counter to increase your Armour Class by your Charisma modifier as a concentration effect until you use another Fel Counter.

Fel Surge

Starting at 14th level, you can choose to keep a number of Fel Counters equal to your Charisma modifier whenever you take a short or long rest.

Explosive Magic

Starting at 18th level, whenever you spend a Fel Counter to improve damage, gain temporary hit points equal to the total additional damage gained from the Fel Counters.