Changeling

A scruffy looking human enters into the alleyway after an elf, and a few moments later the same elf emerges wiping blood off a dagger, but the eyes are still human.

A half-orc slips in and out of the crowd and just before she strikes she shifts appearances to look like a rival gang member.

A jealous suitor changes his appearance to that of a rival that has won the affections of a woman they compete for.

Those rogues that choose this path are either part changeling or have learned some lost art that allows for the changing of physical appearance down to a microscopic level.

 

Alter Being

Starting at 3rd level you can cast Alter Selff on yourself. You can change your appearance of your self, your clothes, and alter the sound of your voice to anyone you have interacted with. You cannot copy a target’s voice if you have not heard them. You can do this a number of times equal to your proficiency bonus per long rest.. 

Also, if you study a person’s handwriting for at least an hour you can create forgeries that can only be found out if someone makes an investigation check with a DC equal to 8+proficiency bonus+charisma.

You can also choose to become proficient in either persuasion or deception, when you reach 11th level you gain proficiency in the skill that you did not choose.

Assimilate Knowledge

Starting at 9th level you can force a target to make a DC Wisdom save equal to 8+proficiency bonus+Cha modifier. If the target fails you can gather certain aspects of an individual. You gather their mannerisms, habits, and certain information about what they know (based on DM’s discretion) For example: if you wished to gain the names of a target’s family, the combination to a safe, or the location of an object, you could perform this ability. The target has disadvantage on the save as long as they are asleep or unconscious. If they fail they also have no knowledge of your mental pilfering.

If the target is successful on the save they become aware of your attempt and you suffer 1d6+target’s CR psychic damage. If you suffer more than 10 damage in this manner you must make a constitution saving throw, on a fail you are stunned until your next turn, on a save you only suffer the damage. 

 

 

Body Change

Starting at 13th level You’ve gained enough control over your being to change certain parts to even more extremes, and can cast an improved version of the Alter Self spell on yourself. The duration of this spell lasts one minute.

Extra Limbs:

Can sprout an extra pair of arms allowing for advantage on dexterity and strength checks.

Can sprout batlike wings to give you a fly speed equal to your walking speed.

Hardened skin: can grant you a +1 bonus to your ac.

Note: those are just examples. Talk with your DM about the extent of these abilities and how they might work in combat, social situations, or everyday life.

Mastery Over Form

Starting at 17th level you have become a master over your physical being.

You are now immune to diseases and poisons, effects that cause advancing or the reversing of aging, have advantage against spells that force changes to your physical form, and have an increased lifespan. For every 5 years of aging you age as if only 1 had passed.

In addition you can now change your form as if you have cast the Polymorph spell. If someone tries to dispel this effect with Dispel Magic you gain advantage on your saving throw.