dark vision 

When a creature you can see makes an attack roll against you, you can use your reaction to impose disadvantage on the roll. You must use this feature before knowing whether the attack hits or misses. Using this trait reveals your shapeshifting nature to any creature within 30 feet that can see you. Once you use this trait, you can’t use it again until you finish a short or long rest.

• You decide what you look like, including your height, weight, facial features, the sound of your voice, coloration, hair length, sex, and any other distinguishing characteristics. You can make yourself appear as a member of another race, though none of your game statistics change. You also can’t appear as a creature of a different size than you, and your basic shape stays the same; if you’re bipedal, you can’t use this trait to become quadrupedal, for instance. Your clothing and other equipment don’t change in appearance, size, or shape to match your new form, requiring you to keep a few extra outfits on hand to make the most compelling disguise possible.
• Even to the most astute observers, your ruse is usually indiscernible. If you rouse suspicion, or if a wary creature suspects something is amiss, you have advantage on any Charisma (Deception) check you make to avoid detection.

You gain proficiency with one tool of your choice. Define a unique identity associated with that proficiency; establish the name, race, gender, age, and other details. While you are in the form of this persona, the related proficiency bonus is doubled for any ability check you make that uses that proficiency.