Kairos Praxis Sorcery

Kairos Praxis - The correct or perfect moment of action or realization. Sorcerers with this bloodline are born with the knowledge of how to maximize and capitalize on these moments. Kairos Praxis Sorcerers are masters of fire magic with an instinctive grasp of when and where to ply their gift. Their inherent understanding of the vibrations of matter and energy gives them to manipulate and control the intensity, strength, spread of flames around them. This nature could come from a natural quirk of their perception of the universe, being born during or after a great blaze, surviving a massive explosion as a child, or from spirits of fire such as elementals or Djinn influencing their ancestry. One way or another, they have been granted a greater understanding and they wield it with startling proficiency. 

Kairos Praxis sorcerers are assets to any adventuring party for their sheer literal firepower and their absurd luck. "But did you die?" is perhaps their favorite question as they hurl gouts of flame and fulminous explosions at enemies with seemingly reckless abandon and perhaps a bit of manic glee. 

Kissed by fire

The arcane magic you command is infused with elemental Fire. You can speak, read, and write Primordial. Knowing this language allows you to understand and be understood by those who speak its dialects: Aquan, Auran, Ignan, and Terran.

Immolative Magic

Starting at 1st level, immediately after you cast a spell of 1st level or higher, you can use a bonus action on your turn to cause whirling shield of elemental fire to briefly surround you until the beginning of your next turn. Doing so grants you a +1 bonus to armor class and any creature that would attack you takes 1d4 + your charisma modifier points of fire damage. 

At level 12 this AC bonus increases to + 2, and at level 18 it increases to +3. 

At level 10 this damage increases to 2d4 + your charisma modifier, 3d4 at level 15, and 4d4 at level 20. 

Expanded spell list: Flame Blade, Flame Strike, and Fire Shield have been added to your spell list. 

Backdraft

At 6th level, your instinctual grasp of the rhythms and flows of energy through reality grants you the ability channel and direct the energy of fire spells. Thus, allowing you to diffuse energy from enemy fire spells and channel the excess energy of your own fire spells. You may channel this ambient energy surrounding you, using it to excite the air around your targets, and at the perfect moment, cause it to ignite scorching them. You gain resistance to fire damage. Whenever you cast a spell of 1st level or higher that deals fire damage, you may spend your reaction to have a number of creatures of your choice within 15 ft. of you, up to your charisma modifier, take fire damage equal to 1/2 your sorcerer level (rounded down) + your charisma modifier. 

Fortuitous Frequency

At 6th level, 

With their instinctive knowledge and understanding of the vibrations of the world around them, and the ebb and flow of its energy, Kairos Praxis Sorcerers and those around them have an almost unnatural, and often infuriating, luck. You gain the ability to subtly bend the vibrations of the world to your haphazard whims and impeccable timing.  You may spend your reaction to have yourself or a creature within 15 feet of you roll an additional d20 on a single attack roll, ability check, or saving throw.  The creature will roll these D20's and you may choose whichever result you prefer. You may utilize this ability a number of times equal to your charisma modifier each long rest. 

Praxic Potentiality

Your intuitive grasp of the ebb and flow of the reality's energies reaches its peak, improving your affinity to, and the potency of, the flames you command. Further, as you become more consciously attuned to reality's tides and shifts you find that your enemies seem to struggle to avoid your spells, or even accidentally stumble into them. Finally, you seem to instinctually disperse hostile fire energy, and diffuse lighting and radiant energies. 

At 14th level,  when a spell you cast deals fire damage to one or more creatures, you may have it deal additional damage to those creatures equal to 1/2 your sorcerer level + your charisma modifier. 

If a spell you cast that deals fire damage has an area of effect increase that area by 10 feet. 

If you make a spell attack roll with a spell that would deal fire damage you may make the spell attack roll at advantage. 

You gain immunity to fire and resistance to lightning and radiant damage.

Kairosis

You have completely integrated your intuitive comprehension of energies ebb and flow throughout the universe. Your fires burn hotter, brighter, more persistently, and more ravenously. Your flames hunger to consume all they touch forcing the matter of their victims to oxidize until it combusts and ignites. This  intensity has the potential to ignite even things normally considered inflammable. These fires burn viciously and ferociously, remaining unquenchable in the face of mundane and magical methods of extinguishing them. 

At 18th level, when you inflict fire damage to a creature that creature must make a Constitution saving throw. Should they fail, they catch fire and burn for up to one minute, these flames cannot be put out by any magical or mundane means. At the start of their turns, creatures burning this way take damage equal to one half of the initial fire damage that sets them ablaze. At the end of each of their turns, a creature burning this way may make a new saving throw. If they succeed the flames subside. If they fail they take 1 point of constitution damage, and continue to burn. A creature with fire immunity or fire resistance is immune to this ability. 

If one of your spells or class features would deal fire damage to a creature and that damage is prevented or reduced by fire immunity or fire resistance, you may spend your reaction to force the creature to make a Constitution saving throw. If the creature fails the saving throw that creature loses fire immunity and gains fire resistance, or loses fire resistance for 1 minute. A creature that succeeds at this saving throw is immune to this ability for 24 hours.  

On your turn, you may spend your action to force a burning creature to make a Constitution saving throw, if the creature fails the creature gains fire vulnerability for one minute. If the creature makes the save, they are immune to this ability for 24 hours. You may activate this ability a number of times equal to your Charisma modifier per long rest.