Mark of the Void

Your innate magic comes from a connection to the void energies of the outer planes. This void energy might have bonded with the essence of your ancestor who travelled the Void and lived to tell the story. Perhaps you were touched by a being of pure magic when you were a child, Perhaps you reached out to the void in an attempt to commune with the mysterious powers that stalk these planes. Occasionally  mysterious and powerful aberrations form the void connect with the mortal planes in an attempt to gain reverence, Leaving their mark on their followers as a symbol of power. Sorcerers with the mark of the void are driven by a primal need to consume.They are naturally attracted to Sources of Immense Magic and Energy, drawn to them like a moth to a flame. Each Sorcerer with this origin has a unique mark of the void usually manifesting itself as a birthmark of a rune or mysterious symbol. The mark pulsates and glows with arcane and void energy when the vessel channels or evokes magic. Looking directly at the mark feels like you are peering through a portal into the vast emptiness of the void.

Mark of the void

The meditating sorcerer stills her mind as she attempts to commune with the void. As she opens a portal in her minds eye, her thoughts are flooded with incomprehensible whispers. A mysterious symbol burns itself onto her neck. This mark of the void pulsates with arcane energy as her connection with void steels her will with a new purpose. Consume...

At 1st level a Mysterious symbol appears on your body.

The mark of the void counts as a spellcasting focus. The "Consume Life" and "Consume Magic" cantrips require the mark of the void to be exposed and pointing  in the general direction for these cantrips to cast.

Your will and resolve is empowered as the mark manifests itself on your body. You gain +1 charisma.

Your presence gives off a shimmering aura as your mark pulsates with arcane energy. You have an Unarmoured AC equal to 10 + your charisma modifier.

Arcane Hunger

Whispers from the void, permeate through your mind. Consume... Consume it all... Your hunger for the essence and arcane energies of the world around you becomes insatiable as you are drawn to increasingly more powerful arcane signatures.

At 1st level arcane hunger grants the "Consume Life" and "Consume Magic" cantrips. These cantrips are always known and count towards the number of cantrips you know. Whenever "Consume Life" or "Consume Magic" would restore sorcery points and you are at max sorcery points, restore hitpoints equal to your proficiency bonus instead.

As your power grows, so does your need to consume. Starting at 5th level, if you spend a day without casting "Consume Life" or "Consume Magic", gain 1 level exhaustion. When you are inflicted with exhaustion in this way, remove 1 level of exhaustion each time you successfully cast "consume Life" or "Consume Magic".

Consumed infusion

As the flames dive into the mark of the void exposed on the sorcerer's chest, He turns to the fumbling mage who launched them at the rogue. His aura flares as he is infused with the Power of the spell. The fumbling mage stares in shock as the flames he evoked, come hurtling back at him.

From the 6th level a consumed spell is stored for up to an hour, or until you consume another spell or essence. You can cast this spell with proficiency, Expending sorcery points = 2 x "the spells level" to do so. Spells cast in this way do not use a spell slot.

An essence is stored when you make a killing blow with "Consume Life", that is stored for up to an hour, or until you consume another spell or essence. The essence grants you the ability to communicate with creatures of the same type and grants you insight into the consumed creatures motive.

Unstable Power

The  gnoll's flanking the sorcerer are sent flying as a powerful wave of force explodes outwards. The sorcerer is left exhausted on the ground as the power of the detonation drains his inner power.

At 14th Level gain the powerful void detonation ability. A powerful explosion of force emanates out from you with increasing levels of power, depleting your sorcery points and potentially leaving you exhausted. Each creature within range has to make a charisma saving throw. On a successful saving throw, deal half damage and knock-back half as far. Once void detonation has been used you must finish a long rest before you can use it again. Void detonation can be altered with Metamagic. Void detonation has a range of 10 x (Void detonation level)feet, deals 4x(Void detonation level)d6 force damage, and knocks back 10x(void detonation level) feet.Spend 4 x (Void Detonation level) sorcery points to cast. Gain 1 level of "arcane hunger" exhaustion for each level of void detonation cast, above 1. Max level of void detonation is 4. 

Echo of the void

The sorcerer  glimmers as he reaches forward and launches a fireball at the warband rushing to attack. Void energy coalesces in front of his mark and bursts into an echo of the void. Sending a second Fireball hurtling towards the devastated warband.

At the 18th Level you gain the "echo of the void ability". Whenever you cast a spell, you can activate the "echo of the void" ability to cast an exact copy of the spell, in the same action. Spend sorcery points = to 3 x (the spells level) to activate. Gain 1 level of "arcane hunger" exhaustion for each multiple of 4 sorcery points spent in this way. A spell cast in this way does not use a spell slot. Can only be cast once per day. Cannot cast spells greater than 4th level in this way.