The Elder Brain

To the mortal mind, life is but a reflection of our perception. We might see this as reality, but that is far from the truth. To those that learn of the Elder Brain, our "reality" is nothing more than an illusion. With enough willpower, anything can be changed, altered. One's psyche is at the whims of its perception. The Elder Brain, a hivemind of both aberration and man, seeks to twist the consciousness and then fully engulf it, slowly but surely connecting all minds and souls into one single omega-being, whose perception is endless and whose dreams are all encompassing. And by the will of the Elder Brain, all will become part of a true reality, a simulated one, where existence is boundless. Warlocks that serve the Elder Brain adhere to this will. Their aim is to bring new victims into the true reality provided within the Elder Brain. With illusion, enchantment and psychic abilities, these warlocks make for unmatched manipulators and knowledgeable spies.

Expanded Spell List

1st-level Elder Brain feature

The Elder Brain 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.

Elder Brain Expanded Spells

Spell Level	Spells
1st	command, silent image
2nd	blur, detect thoughts
3rd	nondetection, sending
4th	compulsion, phantasmal killer
5th	creation, geas

Passage To The Mind

1st-level Elder Brain feature 

Due to the perturbing Elder Brain abilities, no mind attacked by you is safe. Whenever you charm or detect the thoughts of a creature with a spell or ability, you gain an insight into their existence. You can choose to learn one of the following things about it: its skill proficiencies, if it has any; its Intelligence, Wisdom and Charisma scores; or its damage resistances, immunities and vulnerabilities. Instead of learning any of the following, you can choose to burrow yourself deeper within the creature's mind, granting it disadvantage on its next saving throw against a charm effect you force it to make. You can use this feature a number of times equal to your Charisma modifier per long rest.

Mark of The Mind

6th-level Elder Brain feature

Using the power of the Elder Brain, your mind can strengthen and become an impenetrable fortress, which feeds on the psyche of others. After you deal psychic damage to a creature with a spell or ability, you may choose to mark it. You have advantage on all Intelligence, Wisdom and Charisma saving throws that the marked creature forces you to make. A mark on a creature will remain until you take a long rest, and you can mark creatures up to a number of times equal to your charisma modifier per day. 

In addition, while a creature is charmed or marked by you, each time you inflict psychic damage to it, you deal an additional psychic damage equal to your charisma modifier.

Elder Connection

10th-level Elder Brain feature

Your connection to The Elder Brain has become inseparable, and you are able to track potential new members to add to its consciousness. You are always aware of the location of any creature capable of thought (Creatures with an intelligence score of 5 or higher), within 120 feet of you as long as they are on the same plane of existence. You may cast the detect thoughts spell at will (without expending a spell slot) on any creature within this range, but no more than once per creature per day. You do not know the creature's identity, name or species, but you know its exact location and cannot be surprised by it. You may cast the detect thoughts spell at will (without expending a spell slot) on any creature within this range, but no more than once per creature per day. 

Invasive Charm

10th-level Elder Brain features

Your magic has the ability to pierce through a creature's innate defences against charms. When you cast a spell that charms at a creature with immunity to the charmed condition, they instead have advantage on the saving throw, rather than the spell having no effect. Additionally, when you are forced to make a Constitution saving throw to maintain concentration on a spell that imposes the charmed condition, you have advantage on the saving throw.

Infinite Hivemind

14th-level Elder Brain feature

Using the reality-altering powers of the Elder Brain, you can implement false memories into any creature you gain control over. Whenever a creature is charmed by you, you may choose to erase its memories and instead give it new ones. Right before the charm ends, you can replace the memories of events that happened while the creature was charmed. You may not do this if the charm is dispelled. In addition, as an action you may attempt to cast the charm person spell on any number of creatures within 120 feet of you that you can sense. Creatures do not realise that a spell was cast, and when the spell ends, the creatures don't know they were charmed by you. Once you've used this ability you must take a long rest to use it again.