Disquieter

Some rogues learn to harness the terror they inspire.  These rogues use fear to achieve control of their targets.  Some of your fear features require your target to make a saving throw to resist the feature's effects.  The saving throw DC is calculated as follows:  8 + your Proficiency bonus + your Charisma modifier.

Bonus Proficiency

When you choose this archetype at 3rd level, you gain proficiency in the Intimidation skill if you don't already have it.

Siphon Fear

At 3rd level, you can compel a creature to divulge its deepest fear to you.  As a bonus action when you hit with a Sneak Attack you can choose to attain the target's fear.  The target is frightened by you until the end of your next turn, and you mentally learn the frightened target's deepest fears.  You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

Horrific Whispers

Also at 3rd level, you can use a siphoned creature's deepest fears to control how lesser fears affect them.

Horrors Known.  When you gain this feature, you learn two Horrors of your choice, which are detailed in the "Horrors" section.  Each time you gain a level in this class, you can replace one horror you know with a different one.  You can learn one new horror at 9th and 17th level.

Using Horrors.  You can use a horror by meeting the requirements in the "Horrors" section and squeaking the target's deepest fear out loud.  To use a horror, you must have obtained the target's fear via the "Siphon Fear" feature.

You can use the Horror feature a number of times equal to your proficiency, and you regain all expended uses when you finish a long rest.

Fear of Ailment

When you hit with a Sneak Attack, you can cause the target to be poisoned.  At the end of each of their turns they can make a Constitution saving throw against your save DC, ending the effect on a success.

Fear of Exhaustion

When you hit with a Sneak Attack, you can cause the target to suffer one level of exhaustion.  You can only make a creature suffer up to two levels of exhaustion this way.

Fear of Failure

When a target whose deepest fear you know fails an ability check, misses an attack, or fails a saving throw, you can give them disadvantage on their next attack roll, ability check, or saving throw.

Fear of Falling

When you hit with a Sneak Attack, you can cause the target to be knocked prone.

Fear of Heights

When you hit with a Sneak Attack, you can cause the target to be Reduced as per the Enlarge/Reduce Spell.  At the end of each of their turns they can make a Constitution saving throw against your save DC, ending the effect on a success.

Fear of Pain

When you hit with a Sneak Attack, you can deal an extra 2d4 piercing damage to the target.

Fear of Trap

When you hit with a Sneak Attack, you can wrap a creature in webbing.  The target has their speed reduced to 0 and they can't use reactions until the end of your next turn.

Chilling Rebuttal

At 9th level, you can inflict fear upon your enemies when they would dare to attack you.  When you use your Uncanny Dodge feature, whisper fear into your attacker.  When you do, you cause your attacker to make a Wisdom saving throw against your Disquieter save DC.  On a failure, the creature is frightened of you until the start of your next turn.

Unsettling Presence

Also at 9th level, your control over fear allows you to siphon the fear from those who have deep barriers.  You can use your Siphon Fear and level 9 features on creatures immune to the frightened condition.

Primal Fear

Starting at 13th level, your mastery of terror allows you to tap into a primal, evolutionary fear that plagues all sentient creatures; darkness.

Darkness:  When you choose this option, you gain the ability to control the fear of the dark.  As a bonus action, Magical Darkness spreads from a point within range to fill a 15-foot radius sphere for the duration.  The darkness spreads around corners.  A creature with darkvision can't see through this darkness and nonmagical light can't illuminate it.  You can see clearly through the darkness and can teleport to ay point within the darkness a cumulative number of feet equal to your movement.

Ego Death

At 17th level, you gain control over the fear of isolation.  As an action, you can force a creature to make a Wisdom saving throw against your save DC.  On a success, nothing happens.  A creature that succeeds is immune to this effect for 24 hours.  On a failure, the target is blinded, deafened, and under the effect of the Silence spell for a minute.  Other creatures have disadvantage on checks to perceive them for the duration.  The target can repeat the save whenever they take damage.  You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.