Formless

You have awoken the mist that lay dormant within, or maybe you are making the most of a gift given to you by some higher being. Whichever it may be, you now wield the fluidity of the mist, allowing you to access a variety of elements at your disposal, letting you strike from afar or dig the tip of your dagger deeper.  Rogues who embrace this archetype bend and shape the very elements of the arcane, allowing for a Formless Rogue to stay in the fight long enough to potentially deal the final blow, or harm a being with extreme ferocity.

Formless Adaptation

When you choose this archetype at 3rd level, the Mist within you manifests itself from the wellspring within. You gain proficiency in Arcana and Nature. Additionally, when you deal Sneak Attack damage to a creature, you can choose to change the damage type to either fire, cold, lightning or thunder.

Formless Fangs

At 3rd level, the Mists from within manifest around your enemies in a sudden flash. As a bonus action, you can target a creature within 30 feet of you. That creature must succeed on a Dexterity saving throw or be subjected to a violent bite, taking an amount of damage equal to your Sneak Attack dice on a failure, and only half on a success. The DC for this blast equals 8 + your proficiency bonus + your intelligence modifier. If you use this feature, you forgo your usage of Sneak Attack for the round.

Empowered by the Mist

At 9th level, the Mist flares in excitement, augmenting the elements within. Whenever you hit a creature with your altered Sneak Attack from Formless Adaptation or whenever a creature fails the save against your Formless Fangs, you can to trigger one of the following Mist Empowerments depending on the type of damage caused by those features:

Damage	Mist Empowerment
Fire	The mists begin to flare around you. Until the start of your next turn, you benefit from the benefits of both the Dash and Disengage actions.
Cold	The mists calcify into a shield of frost. Until the start of your next turn, you gain a bonus to AC equal to your Intelligence modifier.
Lightning	The mist manifests as a vengeful shroud of electricity. Until the start of your next turn, if a creature hits you with an attack, they take damage equal to your Rogue Level + your Intelligence modifier.
Thunder	The mist enhances your strike with deafening reverberation. Creatures within 15 feet of you must succeed on a Constitution saving throw against your Formless Fangs DC or be knocked prone and deafened until the start of your next turn.

 

You can use this feature a number of times equal to your Intelligence modifier, and regain all uses on a short or long rest.

Master of the Mist

At 13th level, you learn to mold the mist into a more malleable shape, granting you access to the stronger elements within. When you use your Formless Adaptation to change your Sneak Attack damage or when you use your Formless Fangs ability, you can now choose to deal Psychic or Force damage. Additionally, you gain the following Mist Empowerment options: 

Element	Mist Empowerment
Force	The mist allows you to briefly manipulate the corporeal. Choose a creature within 60 feet of you. That creature must succeed on a Charisma saving throw against your Formless Fangs DC, which they can choose to willingly fail. On a failure, you swap places with that creature. Creatures can only swap places if they can physically occupy the other creature's space.
Psychic	The mist strikes a visage of terror or splendor into the mind of your victim. The target must succeed on an Intelligence saving throw against your Formless Fangs DC. On a failure, you can choose to either frighten or charm them for 1 minute, or until they succeed on the save at the end of their turn.

Critical Mist

At 17th level the mist shape to your desires, mimicking the spells of those who devote their life to understanding and mastering the arcane. When you finish a long rest, you can choose a spell of up to 6th level from the Wizard or Sorcerer spell lists. Until your next long rest, you can cast that spell once per short rest, ignoring any Verbal or Somatic components as the mist shapes itself to your desires. Any spell used by this feature that is of 5th level or below is automatically up-cast to 6th level. Spells that require Material components are unable to be mimicked. 

Additionally, you no longer forgo your usage of Sneak Attack when you use your Formless Fangs feature, and the number of Mist Empowerments you can use increases to twice you intelligence modifier.