The Vault

All Warlocks weild magic bestowed upon them by a powerful entity, their Patron. Warlocks of the Vault borrow their power from a Patron created by mortals, and artificial reservoir or matrix of arcane might. You yourself might have helped in its formation, or might be a new inductee in an ancient order that watches over their Vault. The order of Warlocks you belong to might be scholars amassing an archive of texts and scrolls, or a sect of jaguar cultists channeling blood magic into an abandoned shrine, or a holy coven collecting divine relics. The Vault itself might by a glowing knowledge-pool, a network of jarred brains, an orb of writhing serpentine flesh with no head or tail, a crypt where magic weapons are stored, or a sentient force helping you collect the pieces of some important artifact. Whatever the exact nature of the Vault or the order that oversees it, the goal is ultimately the same; use the power granted to you to search for more power to add to the Vault.

Expanded Spell List

The Vault lets you choose from an expanded list of spells when you learn a warlock spell. When you chose this Patron at first level, choose a Level 1 Spell from any Class, it counts as a Warlock Spell for you when learning new Spells. Repeat this process for a Level 2 Spell, a Level 3, Level 4, and a Level 5 Spell, each one from any Class of your choice. These spells will act as your expanded spell list, but also help define the nature of your Patron Vault. You might want to work with your DM to help decide exactly what your order and Vault are.

Vault's Bounty

When you chose this Patron at Level 1 you learn an additional Cantrip of your choice from any Class. This counts as a Warlock Cantrip for you but doesn't count against your number of Cantrips known. Additionally, starting at Level 1 you form a bond with a special Arcane Focus. This focus is a gift from the Patron, to aid you in your search, and as such its exact form will reflect the nature of the Vault. It could be carved and jeweled jaguar skull, the mummified hand of a long dead priest, a wrought iron gauntlet, or a small tablet of clear crystal. Regardless of its appearance, the object requires Attunement. While attuned you can dismiss it into a pocket dimension or summon it to your hand as an Action. If you die, or leave the plane its on, its instantly destroyed. A replacement can be summoned by performing a ritual that takes one hour. While holding it, you can attempt a DC10 Arcana Check to cast a Warlock Spell you don't currently know.

Finder and Keeper

At 6th Level your special focus becomes more powerful, granting a +1 bonus to Spell Save DC and Spell Attacks. This bonus will increase as you continue to collect power for the Vault. It becomes +2 at 10th Level, and +3 at 14th Level. Additionally, while holding your special focus you can cast the Identify Spell as a Ritual.

Vested Interest

At 10th level the Vault has amassed enough power that you can effortlessly borrow Cantrips from it. Whenever you finish a Short or Long Rest, you may replace one of the Warlock Cantrips you know with another one from the Warlock Spell List.

Spell Matrix

At 14th level, the Vault has accumulated so much power that it can manifest any spell you desire. As a Bonus Action, you can call to mind the ability to cast one spell of your choice from any class’s spell list. The spell must be of a level for which you have spell slots, you mustn’t have it prepared, and you follow the normal rules for casting it, including expending a spell slot. If the spell isn’t a Warlock spell, it counts as a Warlock spell when you cast it. The ability to cast the spell vanishes from your mind when you cast it or when the current turn ends. You can’t use this feature again until you finish a Long Rest.