Hubris in Blood

Long ago a master of magic and all things arcane saw the coming end of his civilization.  After trying countless and fruitless endeavors, he concluded only the gods could stop the inexorable march of doom.  Many would give up at this point, but he did not.  He spent decades contriving a powerful spell that would give him the power he needed to end the war; the power of a god.  In his arrogance and hubris he thrust himself and took the mantle of the ultimate power of arcane and magic.  All this power and all this knowledge was thrust into him like a river into a small balloon.  It was this moment he learned the folly of his actions; but it was too late.  His mistake cost his civilization dearly and countless people died.  Now he lied dead on the Material Plane, but his spirit lingers; for no god nor fugue plane sought to claim him.  There he lays in eternal damnation forced to relive his failure in bloated form and bloody devastation.  He seeks to one day reclaim his humanity.  Perhaps he believes, in his arrogance, that only he can fix what was broken that day; perhaps he wishes for the autonomy to ensure no other soul ever attempts what he had done in earnest pride; or perhaps he only wants his torture to end.  Whatever the reason, his spirit continues to reach out and offer arcane mastery and power to those with the aptitude.  All in the hopes that he finds the student capable of setting him free once again.

Some Things to Consider:
This Warlock Patron is a good choice for characters who fancy themselves better than others, or for those who want a Wizard flavor added to their Warlock.  When role-playing the arrogance of this pact make sure to still work well with the party as a whole.  You want to uncover secrets and knowledge and become more powerful to fulfill your conceited nature, but you still understand the usefulness of those around you to undergo tasks too difficult for one person to accomplish.  Despite the Hubris in Blood's arrogance, he still worked to save his people and you might want to also embody this ideal.  You might think you're better than others, but you don't belittle their efforts or mock them unless they act in your opposition.  Although not mechanically a feature of this pact you might want to add a theme of blood to your magic to symbolize your pact, but this is purely cosmetic.

Expanded Spell List

The Hubris in Blood pact lets you choose from an expanded spell list of spells when you learn a warlock spell.  The following spells are added to the warlock spell list for you.

Hubris in Blood Expanded Spells

Spell Level	Spells
1st	Magic Missile, Shield
2nd	Aganazzar's Scorcher, Arcanist's Magic Aura
3rd	Blink, Lightning Bolt
4th	Fire Shield, Stoneskin
5th	Arcane Hand, Wall of Stone

Arcane Arrogance

Starting at 1st level, the nature of your pact instills within you the arrogance of the Hubris in Blood.  Whenever you make a Charisma (Persuasion) check, that check is made with disadvantage.  Also, you can use magical items as if you were a Wizard.
In addition, when you force a creature to make a saving throw from a spell that you cast (this includes spells cast from magic items) you can use your reaction to reduce the number they roll by an amount equal to your Intelligence modifier.  You must declare that you are using this feature before the creature rolls.  You can use this feature once per short or long rest.

Prideful Analytics

At 6th level, you learn to notice and deduce the effects of magic around you and latent in objects and your surroundings.  You are under the effect of a permanent Detect Magic spell.  
In addition, this insight can allow you to accurately deduce the power (what level the spell is cast) or nature (Hostile or Helpful) of a spell you can see being cast within 60 feet of you.  This feature allows you to attempt to take proper cover from a spell that would effect you.  When you are subjected to a spell effect that allows you to make a saving throw to take only half damage, you can use your reaction to instead take no damage if you succeed on the saving throw, and only half damage if you fail.

Touch of Hubris

Beginning at 10th level, your patron teaches you how to dispel magic with a simple touch.  Once per short or long rest, as an action, you can touch a creature or an object and cast a powerful Dispel Magic effect without expending a warlock spell slot.  The level of the Dispel Magic cast is equal to one-half of your warlock level (rounded down).  If the target is an unwilling creature, make a melee spell attack against the target to see if you can touch that creature.
If you target a permanent spell effect you can attempt to nullify its magical properties.  The magical effect makes a Charisma saving throw (using either the original caster's Charisma saving throw or a sentient magic effect's Charisma saving throw [ie. sentient magic items] against your spell save DC.  On a failure, the magic effect is dispelled for a number of minutes equal to your Intelligence modifier and on a success nothing happens and you cannot attempt to use this feature on it again for at least 7 days.

Prestige of Conceit

At 14th level you gain greater control over the overwhelming arcane magic that your patron gives you.  Once per short or long rest, as a bonus action, you can split one of your warlock spell slots into multiple, lower level spell slots.  For example, a 5th level warlock spell slot could be turned into a 4th level spell slot and a 1st level spell slot, or a 2nd level slot and a 3rd level slot, or into two 2nd level slots and a 1st level slot, or five 1st level slots.  This feature expends the spell slot that is being split.  Only one spell slot can ever be split at a time.