The Thrall of Ashiok is someone who has, for one reason or another, taken up service with Ashiok, gaining powers and abilities to manifest in peoples dreams as well as remove their memories or manufacture new one.

Ashiok, also known as the Dream Render, is a mystery like a half forgotten dream. It appears in dreams and vision and also walks the planes in material form. Some view Ashiok as an Archfey, others as some ineffable entity from the Far Realm. Where Ashiok goes so to do nightmares, visions, portents, dementia and madness. Ashiok does not seem to be an evil entity, just above the concerns of mortals and immortals alike and it appears to take some form of sustenance from the dreams and memories of those are around it.

Ashiok can appear in any form it desires but its natural form is of a roughly humanoid body wrapped in billowing diaphanous robes of black and bronze colours that gradually evaporate to become smoke-like and float around it like ghostly tentacles, causing it to drift as if levitating or swimming in some unseen sea. It has skin of a light blue/grey and has a head which only exists up to the bridge of the nose, everything else above this dissolves into two blackened horns that constantly evaporate into the same smokey substance that its robes are made out of.

(for an image of Ashiok, see the Magic the Gathering card: Ashiok, Dream Render)

Expanded Spell List

The Thrall of Ashiok the Dream Render 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.

Expanded Spells:

Level 1: Dissonant Whispers, Sleep

Level 2: Invisibility, Phantasmal Force

Level 3: Bestow Curse, Nondetection

Level 4: Greater Invisibility, Phantasmal Killer

Level 6: Dominate Person, Modify Memory

Dream Render

Starting at 1st level, You can choose to meditate as part of your long to observe the dreams of another individual you can see within 20ft.

You cannot interfere in their dream or recall any specific details about what they dreamed without the use of the Dream spell. Upon waking the subject you observed has a vague recollection of dreaming about you in some fashion.  Once the Long rest is complete you siphon of some of their dream and gain one of the following options:

1) Choose one 1st-level spell that the individual knew. You can cast it at its lowest level ONCE. If you do not use this spell it disappears from your memory at the start of your next long rest.

2) Choose a skill the individual knew. You may make one check with that skill as if you had Advantage. If you do not use this ability it disappears from your memory at the start of your next long rest.

Dreams Fade

At 6th level, You can fade from sight like a barely remembered dream.

As an action, you become invisible until the end of your next turn. You become visible if you attack or cast a spell. You can use this ability twice per short rest.

Subtle Caster

Starting at 10th level, You learn to mask your spell casting talents to some extent.

Spells cast using your Pact Magic spell slots, Cantrips gained from the Warlock class or Cantrips and spells gained via the Magic Initiate: Warlock feat are cast as if you had used the Sorcerer meta-magic ability: Subtle Spell.

Spells cast using spell slots form other classes, Cantrips from other classes and Cantrips and spells gained from other Magic Initiate classes do not gain this benefit.

Waking Nightmare

Starting at 14th level, you learn how to make someone experience their worst nightmare and make it a reality for them. You can cast the spell: Mental Prison once per Long Rest without using a spell slot.