Sorcerous Origin - Pyrosoul

Your arcane soul is one of pure fire. Sorcerers with this bloodline may have a connection to the elemental plane of Fire, to the nine hells, or perhaps you were simply born under a particularly fiery star. Regardless of your origins, your grasp of fire magic is as powerful as it is explosive, threatening to incinerate not just your enemies but yourself as well. Inherently a destructive magic, pyrosoul sorcerers rarely find themselves using their gifts for peaceful purposes, instead often serving in adventuring parties or militaries as powerful spell-based artillery.

Optionally your soul may manifest in a number of physical ways. If you so choose, roll or pick one of the following from the table below.

Manifestation
d6 Manifestation
1 Parts or all of your hair may be replaced or singed by flame that always burns but never harms you.
2 You are always accompanied by the faint scent of smoke and ash.
3 Your irises shift and change as if burning flames sit just behind your eye.
4 Your skin is always warm to the touch, even in the coldest cold.
5 You give off a faint elemental aura that those especially attuned to magic can detect, either naturally or with the spell Detect Magic.
6 When you walk bare foot, you leave slightly singed footprints in your wake. You may need to replace your boots often.

Heat Up

When your bloodline awakens your gain a direct affinity for fire spells. You learn how to siphon off excess heat and use it to fuel your damage further. You gain a Heat Die, which you roll in addition to any damage dealt by a fire-damage spell. This heat die grows as in the table below starting from 1d4, to 1d6, to 1d8, to 1d10, to 1d12, and to a maximum of 1d20, growing after the spell is cast. After dealing damage with a d20 heat die, you Overheat, and take fire damage equal to the amount you rolled on your d20 heat die and resetting the die back to 1d4.

Heat Die
Spell Level Heat Die Increase
Cantrip +1/2
1st-3rd +1
4th-5th +2
6th-7th +3
8th-9th +4

If you spend a turn without casting a fire damage spell, your heat die goes down one size. If you cast a cold damage spell, your heat die goes down two sizes.

In addition, you automatically learn a number of spells detailed on the table below, which do not count against your normal list of sorcerer spells.

Pyrosoul Spells
Sorcerer Level Spells
1st Burning Hands, Searing Smite
3rd Scorching Ray, Heat Metal
5th Fireball, Protection from Energy
7th Fire Shield, Wall of Fire
9th Flame Strike, Immolation

Vented Flames

From 6th level your heated soul spills out around you. While you have a heat die active, any cold or fire damage dealt to you is reduced by an amount equal to your current heat die. Overheat damage cannot be reduced by Vented Flames due to its explosive nature. You also shed bright light within 10' of yourself, and whenever a creature within 5 feet of you hits you with a melee attack they take damage equal to your heat die.

In addition, you have immunity to exhaustion from extreme cold weather.

Promethean Inferno

From 14th level your fire singes even heaven and hell. Any creature's immunity to fire damage is instead treated as resistance to fire damage instead for your fire damage spells. If you have the Elemental Adept (Fire) feat, these downgraded immunities are likewise removed, just as with normal fire resistance.

Pyromastery

At 18th level your soul becomes one with the flames. You gain immunity to fire damage. In addition, any fire damage spells you cast can have a metamagic you know applied to them without costing sorcerer points. You can then spend sorcery points to apply a second, different metamagic to the same spell as normal if you so wish.