Vryss of Kendun

Assassinate. During her first turn, Vryss has advantage on attack rolls against any creature that hasn't taken a turn. Any hit she scores against a surprised creature is a critical hit.

Cat Instincts.  You are quick to spring to action, gaining a bonus to initiative equal to your proficiency bonus.

Viper Tongue.  You can detect poisons by taste and have resistance to poison damage.

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

Sneak Attack. Once per turn, Vryss deals an extra 14 (4d6) damage when she hits a target with a weapon attack and has advantage on the attack roll, or when the target is within 5 feet of an ally of the Vryss that isn't incapacitated and the assassin doesn't have disadvantage on the attack roll.

Witcher Signs.  Witchers wield a unique form of magic developed for monster-hunting called Signs, which they can cast any number of times up to their wisdom modifier per long rest.  Empowering a sign spends an additional charge.  Vryss can cast the following signs at will, without expending a charge:

Axii: You make yourself appear more menacing than usual in the minds of your onlookers (e.g. your eyes flash, your teeth sharpen, your face is draped in shadow), granting you advantage on Charisma (Intimidation) checks for as long as you maintain concentration.

Igni:  You light or snuff a candle, torch, or small campfire within 30 feet.

Multiattack.  Vryss makes two shortsword attacks.

Shortsword (Silvered). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) piercing damage.

Light Crossbow (Poisoned). Ranged Weapon Attack: +6 to hit, range 80/320 ft., one target. Hit: 7 (1d8 + 3) piercing damage, and the target must make a DC 15 Constitution saving throw, taking 24 (7d6) poison damage on a failed save, or half as much damage on a successful one.

Igni.  Ranged Sign, range 30ft, one target.  One creature within range must make a DC 14 Dexterity saving throw. On a failed save, the creature takes 2d8 fire damage, and no damage on a successful one.  If you concentrate, you may sustain a stream of fire against the target creature so long as it remains within range, though while doing so your speed is halved.

Empowered Effect: The flames affect all creatures in a 30 foot cone originating from you; they inflict half as much damage on a successful save (instead of no damage), and on a failed save they light the target on fire. A burning target takes 3 (1d6) fire damage at the end of their turn unless someone takes an action to extinguish them. In addition, the fire ignites any flammable objects in the area that are not worn or carried.

Axii.  Witcher Sign, range 30ft.  Choose a living humanoid within range and force it to make a Wisdom saving throw. If you or your companions are currently fighting the humanoid, it has advantage. If the humanoid fails its save, it is stunned as long as you maintain concentration. If you or your companions do anything harmful to it, the effect is broken.

Empowered Effect: The target humanoid is charmed if they fail their Wisdom save, does not remember being charmed, and casual onlookers cannot detect the charm.

Shroud of the Twincloak.  As an action, this sister can throw a smoke bomb that creates a heavily obscured area in a 20-foot radius.  A moderate wind (at least 10 miles per hour) disperses the smoke in 4 rounds; a strong wind (20 or more miles per hour) disperses it in 1 round.  Alternatively, Vryss can spend an action to throw a bomb in any direction that is within 60ft of her.

Eager Riposte:  When you are wielding a finesse weapon with which you are proficient and another creature hits you with a melee attack, you can use your reaction to make a melee weapon attack against the creature.  Alternatively you can use this reaction for an ally within 5ft of you.