The Sentinel Wyrm Patron

The avowed of Candlekeep take vows when they join the order.

"Let knowledge be a flame to light a dark world, fuel it so it can thrive. Defend against those who would abuse it and snuff out its light"

A rare few take a more proactive approach to Candlekeep's purpose and the responsibilities of the avowed. Miirym, the Sentinel Wyrm of Candlekeep, a ghostly silver dragon bound to the keep as its eternal defender, shares the same view. If an avowed seeks her out and she deems them worthy, she may offer them a pact to be her arm outside the keep's walls.

Alternatively, a Warlock may make this pact to be a champion of truth and knowledge with another similarly minded powerful entity. In this case, adjust the non-mechanical descriptions of the subclass to fit your chosen patron. After all, flavor is free.

Level 3: Sentinel Wyrm Spells

The magic of your patron ensures you always have certain spells ready; when you reach a Warlock level specified in the Sentinel Wyrm Spells table, you thereafter always have the listed spells prepared.

Sentinel Wyrm Spells

Warlock Level	Spells
3	Detect Magic, Sanctuary, Detect Thoughts, Enhance Ability
5	Dispel Magic, Sending
7	Arcane Eye, Leomund's Secret Chest
9	Cone of Cold, Dispel Evil and Good

Level 3: Sentinel Pacts

Your connection to your patron, and their hoard of Knowledge within Candlekeep, grants you benefits through your Pact Eldritch Invocations.

A Hoard of Knowledge: You can access the boundless magical knowledge of Candlekeep through your Book of Shadows granted by the Pact of the Tome invocation. When you create your Book of Shadows, you can add additional ritual spells to the book equal to your Charisma Modifier, minimum of 1. The spells can be up to the level of spell you can cast through your Pact Magic feature.

Sentinel's Scales: You gain the effects of the Mage Armor spell while weilding your Pact Weapon granted by Pact of the Blade. When you conjure your Pact Weapon and are not holding anything in your other hand, you can also conjure a spectral shield resembling a silver dragon scale. You are proficient with this shiled and can still gain the effects of the Mage Armor spell from this feature while you weild it.

Sentinel Wyrm's Projection: If your familiar granted through the Pact of the Chain is a Pseudodragon, it gains Blindsight with a range of 60 feet, and Dark Vision to a range of 120 feet. While perceiving through your familiar you can cast spells as if you were in its space as long as it's within 60 feet of you.

Level 6: Alaundo's Guidance

Your patron allows you to tap into the vast archive or prophecies from Alaundo the Seer locked within the Candlekeep Library.

When you cast a Divination spell that targets another creature with a Saving Throw, the targeted creature has Disadvantage on the Saving Throw against that spell. Additionally, when you cast a Divination spell that allows you to ask the DM a question, you can ask one clarifying question.

Level 10: Gatewarden Pact

Your connection to your patron further strengthens your Pact Eldritch Invocations.

Knowledge At Your Fingertips: Once per Short Rest you can cast one of the Ritual Spells within your Book of Shadows using its normal casting time.

Sentinel's Blade: When you take the Attack Action on your turn, you can replace one of those attacks with a Warlock Spell or Cantrip that requires and attack roll with a weapon.

Spectral Wyrm: If your familiar granted through the Pact of the Chain is a Pseudodragon, it takes on the incorporeal presence of your patron. Your familiar can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

Level 14: Sentinel's Breath

When you cast Cone of Cold from your Sentinel Wyrm Spells feature, you can attempt to tap into your patron's breath weapon to fuel the spell. Roll a d6, on a 5 or 6 you cast the spell without expending the Spell Slot and the damage type can be either Cold or Necrotic. You can use this feature a number of times equal to your Charisma modifier, and you regain all expended uses when you finish a long rest.