Chance

Change Appearance. The changeling can use its action to polymorph into a Medium humanoid it has seen, or back into its true form. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn’t transformed. It reverts to its true form if it dies.

Lightfooted. Chance can take the Dash or Disengage action as a bonus action on each of its turns.

Evasion. If Chance is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, Chance instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

Artificially Augmented Spellcasting. Chance is a 5th-level spellcaster that uses Charisma as his spellcasting ability (spell save DC 13, +5 to hit with spell attacks). Chance's spellcasting is a result of experimental self augmentation and is fueled by artificer-constructed implants:

1st level (4 slots): fog cloud, magic missile, sleep, charm person,

2nd level (3 slots): invisibility, blur, mirror image

3rd level (3 slots): counterspell, hypnotic pattern, incite greed

4th level (2 slots): arcane eye, greater invisibility

5th level (1 slots): dominate person, far step

Multiattack. Chance makes 2 attacks with its rapier.

Rapier. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) piercing damage.

Unsettling Visage (Recharges after a Short or Long Rest). Each creature within 30 feet of the changeling must succeed on a DC 13 Wisdom saving throw or be frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.