A Warlock Patron based on Srontil, the Dark Windlord.

Expanded Spell List

The Dark Windlord lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Dark Windlord Expanded Spells

Spell Level	Spells
1st	[Tooltip Not Found], False Life
2nd	Levitate, See Invisibility
3rd	Dispel Magic, Counterspell
4th	Polymorph, Phantasmal Killer
5th	Legend Lore, Telekinesis

Remember the Cost

Starting at 1st level, you gain a resistance to Psychic damage. As well, you may cast a spell from a used spell slot once, without using a spell slot. This recharges on a long rest.

Darkness of Betrayal

Starting at 6th level, you can tap into Sorontur's Hatred. You can cast Darkness up to three times without using a Spell slot. 

Once you use this feature, you can’t use it for 24 hours.

The number of uses increases by 1 per Warlock Level.

Windlord's Knowledge

Starting at 10th level, the Dark Windlord gifts you with Knowledge. You can pick Proficiencies or Spellcasting.

Proficiencies

Pick two languages, one weapon, and one skill to gain proficiency in.

Spellcasting

You may pick two 1st level spells, two cantrips, or 1 of each from the Cleric, Wizard, Paladin, or Sorcerer spell lists

Windlord's Wings

At 14th level, you gain the ability to sprout a pair of black feathered wings from your back, gaining a flying speed equal to your current speed. You can create these wings as a bonus action on your turn. They last until you dismiss them as a bonus action on your turn.

You can’t manifest your wings while wearing armor unless the armor is made to accommodate them, and clothing not made to accommodate your wings might be destroyed when you manifest them.