The Eldritch Elder Thing

In your pursuit of knowledge, you have found forbidden knowledge of a mysterious entity whose nature is utterly foreign to the fabric of reality. Instead of turning away from this powerful knowledge, you have embraced it and learned to channel it. It might come from the Far Realm, the space beyond reality, or it could be of the elder gods known only in legends. Its nature is incomprehensible to mortals, and its knowledge so immense and ancient that even the greatest libraries pale in comparison to the vast secrets you now holds. The secrets you have learned allow you to draw your magic from this new source.

Entities of this type include Ghaunadar, called That Which Lurks; Tharizdun, the Chained God; Dendar, the Night Serpent; Zargon, the Returner; Great Cthulhu; and other unfathomable beings

Intelligent Spellcasting

Instead of having charisma as your spell-casting ability for your warlock spells, you can instead use your intelligence to cast spells with. Additionally, any invocation which uses your charisma modifier to determine its effects can instead use your intelligence modifier.

Expanded Spell List

The Elder Thing 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.

Great Old One Expanded Spells

Spell Level	Spells
1st	bane, hideous laughter
2nd	detect thoughts, calm emotions
3rd	clairvoyance, blink
4th	confusion, phantasmal killer
5th	dominate person, dream

Visions of the Far Realm

Every night, your dreams are haunted by the sight of abominations of arcane origins. You have began to analyze and learn more about these monsters. Whenever you make an intelligence check to re-call information about or relating to aberrations, fiends, monstrosities, oozes or undead, you have advantage on the check.

If you spend at least 1 minute recalling information about a creature of any those types outside of combat, then you automatically learn its damage vulnerabilities, resistances and immunities alongside any condition immunities it has.

Deranged Whispers

At 6th level, whenever a creature targets you with an attack roll you can use your reaction to magically generate a disturbing cacophany of discordant gibbering, screaming and crying. Until the beginning of your next turn, attack rolls against you are made with disadvantage.

Once you use this feature, you cannot use it again until you complete a short or long rest.

Bond of the Awakened

Starting at 10th level, your alien knowledge gives you the ability to touch the minds of other creatures. You can telepathically speak to any creature you can see within 30 feet of you. You don’t need to share a language with the creature for it to understand your telepathic utterances, but the creature must be able to understand at least one language. The creature cannot communicate back to you in this way.

However, as an action, you may cast Telepathic Bond without expending a spell slot. When cast in this way, the duration is increased by a number of hours equal to your Intelligence modifier (minimum of 1), and immediately ends if you become unconscious. Once you use this feature, you must finish a Long Rest before doing so again.

Psychic Scream

At 14th level, you gain the ability to emit a maddening scream from your mind. As an action, you can magically expel a 30 foot cone of psychic energy.  Each creature in the cone must succeed an Intelligence saving throw or take psychic damage equal to 6d8 and be stunned until the end of your next turn. On a success, a creature takes half this damage and isn’t stunned.

Once you use this feature, you can’t use it again until you finish a long rest.