Cuprilach

Magic Resistance. The cuprilach has advantage on saving throws against spells and other magical effects.

Hide in plain sight. The cuprilach can take the hide action as a bonus action if there is a a shadow other than its own adjacent to it. 

Swift Strikes. As an action the cuprilach can make their multi attack with all attacks having advantage. Whilst they make these attacks the attacked creature can't take reactions until the end of their next turn. After this is all finished the cuprilach will gain 1d4 levels of exhaustion. 

Calm insight. The cuprilach can't be surprised by any attacker or event that is directly targeting them. 

Sneak Attack (1/Turn). The cuprilach deals an extra 9 (3d6) damage when it hits a target with a weapon attack and has advantage on the attack roll, or when the target is within 5 ft. of an ally of the cuprilach that isn’t incapacitated and the cuprilach doesn’t have disadvantage on the attack roll.

Innate Spellcasting. The  cuprilach’s innate spellcasting ability is Wisdom (spell save DC 16, +8 to hit). The cuprilach can innately cast the following spells, requiring no material components:

At will: Comprehend languages, Detect Good and evil, Detect thoughts, Detect magic, Feather Fall, Knock, Locate creature, Melf's acid arrow, Sanctuary, See invisibility

3/day: Dimension door, Enervation, Mislead 

Multi attack. The Cuprilach either makes two +2 rapier attacks or three +1 Longbow of speed attacks. 

+2 Rapier . Melee Weapon Attack: +11 to hit, reach 5 ft., 1 target. Hit: 12 (1d8 + 8) piercing damage. 

+1 Longbow of Speed. RangedWeapon Attack: +10 to hit, range 150/600 ft., 1 target. Hit: 11 (1d8 + 7) piercing damage.

Variant: Summon Rilmani(1/Day). The rilmani chooses what to summon and attempts a magical summoning.

A cuprilach has a 75 percent chance of summoning 1d3 ferrumachs.

A summoned rilmani appears in an unoccupied space within 60 feet of its summoner, acts as an ally of its summoner, and can’t summon other rilmani. It remains for 1 minute, until it or its summoner dies, or until its summoner dismisses it as an action.