Homebrew
Spellcasting. Helena is a 3rd-level spellcaster with Charisma as her spellcasting ability (spell save DC 11, +3 spell attack bonus). She has the following spells prepared:
Mage Hand Legerdemain. When Helena casts the cantrip Mage Hand, the spectral hand is invisible & can perform the additional tasks:
The above tasks can be performed without being noticed by a creature if she succeeds on a Dexterity (Sleight of Hand) check contested by the creature's Wisdom (Perception) check. She can also control the hand as a bonus action.
Relentless Endurance (1/Day). If Helena is reduced to 0 HP but not killed outright, she can drop to 1 HP instead.
Sneak Attack. Once per turn, Helena can deal an extra 7 (2d6) damage to one creature she hits with an attack if either of the following conditions are met:
Silvered Scimitar. Melee Weapon Attack: +4 to hit, reach 5', one target. Hit: 5 (1d6 + 2) piercing damage. On a critical hit, the attack does 9 (2d6 + 2) piercing damage in addition to critical damage.
Shortbow. Ranged Weapon Attack: +4 to hit, range 80'/320', one target. Hit: 5 (1d6 + 2) piercing damage. On a critical hit, the attack does 9 (2d6 + 2) piercing damage in addition to critical damage.
Cunning Action. Helena can take the Dash, Disengage, or Hide action.