Chosen of the Ruby Lady

The Ruby Lady of Death & Magic is an aloof entity that rarely grants any magical power to her worshipers and thus has relatively few clergy. She does, however, occasionally select individuals from among her devotees to serve as her agents by offering them a pact similar to those made by warlocks and their non-divine patrons. Her contract is simple: access to raw magical power and a longer lifespan in exchange for the immortal essence of the chosen individual.

It is unknown what the Ruby Lady does with the souls of those committed to her contract. While some believe that such souls still wander the multiverse pursuing her inscrutable agenda, others say they are assigned the task of maintaining the paths by which the newly deceased arrive at their final rewards. However, the most common belief is that the energy of these souls is extracted and infused into the very substance of magic itself, thereby destroying the chosen soul utterly.

Eldritch Pact

You have made a pact with the Ruby Lady of Death who now claims ownership of your undying essence after your death. In exchange, your body is infused with raw magical power that grants your ability to cast spells. It also grants the following:

1) You apply double your proficiency bonus to INT(Arcana) checks made in relation to active spells and spell-like effects. This does not include any INT(Arcana) checks made as part of any spellcasting or similar action on your part.

2) You learn one bonus language from the following list: Draconic, Deep Speech, Primordial.

Deep Speech

The language of ancient subterranean monstrosities such as aboleths and cloakers

Draconic

The language of dragons

Primordial

The language of elemental creatures

Eldritch Fortification

You can use some the raw magical power granted to you by the Ruby Lady to heal your body's injuries or to protect yourself from attack. On your turn you can activate this feature to use one of the following effects:

1) On your turn, use a bonus action to regain hit points equal to 1d6 + you sorcerer class level. 

2) Use your reaction to add a +4 bonus to AC until the beginning of your next turn. You may only use this application of this feature after an attack is rolled against you but before the result is determined. Requires 6th level.

3) Use your reaction to reduce the effect of a critical hit against you to a normal hit. You may only use this application of this feature after a critcal against you is declared but before damage is calculated. Requires 14th level.

You may not use this feature again until after you have finished either a short or a long rest.

Eldritch Substitution

When you cast a spell that deals damage you can substitute its energy type with another. You can use this feature a number of times equal to your CHA modifier. You regain all uses of this feature after a long rest.

Eldritch Infusion

When you cast a spell that deals damage you can add your CHA modifier to one damage roll of that spell starting at 14th level and again for every two levels of sorcerer after 14th (2 x your CHA modifier at 16th level, 3 x your CHA modifier at 18th level, and 4 x your CHA modifier at 20th level). You cannot use this feature again until after either a short or a long rest.

Eldritch Siphon

You can steal the life force of another creature to replenish your magical power. As an spell attack action, you target a creature within 60 feet that you can see. That creature must make a Wisdom saving throw or have their hit point maximum permanently lowered by 1d10. The link lasts for 1 minute or until you lose your concentration (as if you were casting a concentration spell). At the beginning of each of your turns you can choose to have the linked creature make a Wisdom saving throw or have their hit point maximum permanently lowered by 1d10 again. For every point the target creature's hit point maximum is reduced, you regain an equal number of sorcery points. If the target succeeds on their WIS save, the effect is ended and the creature is immune for 24 hours. A creature that willingly fails its Wisdom saving throw has its hit point maximum reduced by 2d6 instead of 1d10.