Nightmare

Your mind begins to slip, falling over and over, deep into a dark sleep. What's this? The monsters from your dream don't leave you?

Monsters

Starting at 3rd level your nightmares carry over into real life, the creatures you see in your dreamscape seem to follow you wherever you go and won't even leave your peripherals. Once per long rest you can summon an Undead, Fiend, or Abberation, within 30 feet of you, their CR must be equal to yours or lower. They always have an AC of 5 unless fitted with armor and their HP will always be 10 unless increased by magical means. Once it is killed it will be sent back into your dreamscape. The DM will control them (however, you can negotiate with your DM about this) since they are simply from the deepest reaches of your mind you cannot control them. If you are within 5 feet of your monster you gain sneak attack.

Fear the Mare

Starting at 3rd level your sneak attack strikes fear in those stricken with it. When you use your sneak attack on a target they must make a cons save, DC 8 + proficiency bonus + intelligence modifier. On a failed save they become frightened towards you and are dealt psychic damage equal to half your Nightmare level (minimum of 1), and they must repeat the save at the end of their turn. On a successful save they don't become frightened or take damage. 

Scared?

Starting at 9th level, three times per long rest you may transform a number of allies equal to half your rogue level (rounded down) into aberrations. These forms are merely cosmetic and don't give you any abilities relating to your form other than while in these forms you gain advantage on intimidation checks, all unarmed attacks made by you or the party impose a cons save against the creature being hit DC = 8 + proficiency bonus + intelligence modifier on a failed save the creatures become frightened and must make the save again at the end of their turn, and humanoids have disadvantage on saving throws against being frightened by you. 

Nocturnal

Your constant nightmares keep you awake. Starting at 9th level you may now be satisfied with half the amount of sleep normally needed, and while you do sleep you create an aura around yourself equal to half your level (rounded down) times 5 feet. This aura makes you aware of anything that enters it so you are no longer surprised while you sleep.

13

Starting at level 13, as a reaction to an attack, you can cloak yourself in nightmare giving you a +3 to AC potentially causing the attack to miss. If the attack still hits the creature must make a cons save, DC = 8 + Proficiency Bonus + Intelligence modifier, or become frightened by you. It must make the save again at the end of its turns.

Pure Adrenochrome

Starting at 17th level your tolerance towards fear has made you become immune to being frightened. Once per short rest you may invoke a shroud of fear to surround you and any humanoid that comes within 10 feet of you while this shroud is up won't be able to focus on anyone but you. If you are taken down to zero hit points but not killed outright while this shroud is invoked all creatures within 10 feet of you must succeed a cons save DC 8 + proficiency bonus + intelligence modifier or be frightened by you until the shroud is gone. The shroud lasts for one hour and can only be dismissed by a dispel magic spell.