Order of Brimstone

The Order of brimstone focuses on using Mostly fire and negative energy. To use a mixture of the two hinges on self control, both emotional, physical and mental. and it's power, with the right amount of control, can be devastating, is also highly addicting. Wizards who have gone down this path without the right amount of control end up becoming slaves to power with too little, weather that being seeking lichdom to obtain more knowledge, collecting artefacts to enhance their power, Sought out ways to get to more fiendish sources of power, or simply go insane. With too much control, They will end up becoming a fiery form of their previous selves, without identity or remembering how they became a fire elemental.

When in the right hands and with everything laid out perfectly, The wizard can deal Heavy damage to anyone they please.

Inner fire

Starting ta 2nd level, You gain access to certain fire spells:Produce flame, Hellish Rebuke, Flame blade , Fire storm and Heat metal. These are added to the spells you can learn.

Cauterise

Also at 2nd level, When you deal fire damage to a creature, you can use your reaction to convert half the damage into a healing energy. Fire resistance will half this healing, whilst immunity to fire damage are also immune to this feature. You can use this feature once per long rest.

Brimstone Charge

Starting at 6th level, you get a certain amount of Charges equal to twice your Intelligence mod (minimum of 1). You may spend them in the following ways:

You can use one charge to reroll fire damage of a spell or attack.

You can use one charge to change the damage type of The spell or weapon attack to Fire.

You regain all charges on a long rest.

Additionally, your magic has become volatile enough to become wild. Whenever you cast a spell, use a brimstone charge or if fail a concentration save, roll 1d20. On a 1, roll on the Sorcerer's wild magic table.

Of the abyss

As an action when you reach level 10, you invoke a Charred word and spend 5 brimstone charges. All creatures within 30ft of you (excluding yourself) make a Dexterity save. On a failed save, the creature takes 5d12 fire damage and catches fire. They take half damage and don't catch fire on a successful save. 

A creature that catches fire takes 1d12 fire damage over the course of one minute. A creature can use it's action to end this effect, as it snuffs out the flames with desperate flailing. Entering or dousing the flames in water doesn't end this effect.

Supreme charge

At 14th level, Your brimstone charge is magnifies ten-fold, the following affects your charges:

You regain half your proficiency bonus in charges on a short rest.

You regain 1 charge when you roll a 20 on a spell attack.

When you cast a spell that deals fire damage, you can spend an amount of charges equal to double the spell's level (cantrips cost 1 charge). Instead of rolling for damage of the spell, you deal the maximum amount of damage.