Enigma

Like the quiet murmurings in a crowd, or a single leaf on an autumn forest's bed, the Enigma are one of many, and easily forgotten. Their whispers, however, hold the secrets of cunning plots and schemes. Underneath their leaves, though similar to all others around, lie in wait the venomous snake, or the thread of a tripwire. The Enigma operate unnoticed in plain sight, as if their deeds were performed by the wind itself.

One of Many

At 3rd level, you gain proficiency with the Deception skill, and add double your proficiency modifier when making this check. Creatures of your choice that you can either see or hear, and who can either hear or see you, must make a Wisdom check (Insight) versus your Charisma check (Deception). On a failure, they fail to recognize or remember your features, looks, and voice, and often erroneously characterize you if they attempt to recall these characteristics. This persists even after they can no longer see or hear you. On a success, they will remember your traits, and are immune to this effect for twenty-four hours, though they are unaware of it occuring. Creatures have advantage on this check if you have attacked them or one of their allies within the last twenty-four hours, or if they are friendly and well acquainted with you. Creatures who have succeeded the check may use a bonus action to alert their allies, of whom can re-attempt their checks.

Unseen Threat

Beginning at 3rd level, when a creature fails a check against your One of Many feature, you gain advantage on your next attack or Dexterity check made against them.

Perfect Mediocrity

Beginning at 9th level, you are seen as completely average within all spheres of society, civilized or monstrous alike. Though you are not recognized as a figure of authority while using this feature, you are seen as well versed in the mannerisms and subtleties of different castes, societies, and cultures. This includes any languages they might speak, though you fail to understand them if you are not proficient with said language. Creatures who fail a check against your One of Many feature, or who are not actively searching for you, are not alerted to your failure of comprehension and incoherency of responses, given you do not prolong an interaction beyond reason (DM's discretion).

Additionally, you may intensify your subtle charisma, making yourself seem like less of a threat. You may use a reaction to add your Charisma modifier to your AC and saving throws against effects that target only you until the end of the turn it is used.

Persona of Lethe

At 13th level, you can make yourself simply, forgotten. When a creature that you have not attacked within the last twenty-four hours fails a check against your One of Many feature, you can choose to have that creature forget seeing or spotting you. This includes anything you may have said and any actions you may have taken at the time. This effect, and your One of Many feature, can be extended to three different creatures of your choice that you can see or hear. You may use this feature a number of times equal to your Charisma modifier (minimum 1), and must finish a long rest before regaining any expended uses.

Incomprehensible

Beginning at 17th level, you become nearly incomprehensible, whose actions and strikes come from seemingly nowhere. Once per day, you can become The Enigma. You concentrate on your Enigma form as if on a spell, but when you are forced to make a concentration check you instead make a Charisma saving throw, of which you are proficient for this feature. You must finish a long rest before you can use enter this form again. You benefit from the following effects as The Enigma.

You are treated as if under the Greater Invisibility spell.

Creatures who can see or perceive you through your invisibility are immediately subject to your One of Many feature.

feature. You leave no discernible marks or footprints, and minor disturbances you cause are ignored or attributed to coincidence, foolishness, or simply the wind.

The state persists until you fail a concentration check or until you end it with a free action on your turn.

Artist Credit: https://www.deviantart.com/?section=&global=1&q=ralphhorsley&offset=144