Auxilia Ballistarii

Fey Ancestry.  Advantage on saving throws against being charmed, and magic can't put the Auxilia to sleep.

Pathfinder.  The Auxilia ignores difficult terrain, advantage on initiative, and advantage on attack rolls made against opponents that have not acted on the first round of combat.

Humanoid Favored Enemy. The Auxilia Ballistarii have advantage on Wisdom (tracking) checks to track humanoids and constructs, advantage on saving throws to resist spells and abilites of humanoids and constructs. The Auxilia deals an additional +4 damage to humanoids and constructs.

Expert Ambushers. If the Auxilia prepares an ambush, those seeking to detect them roll with disadvantage and are at a -10 to their Passive Perception.

Fleet Footed. The Auxilia can use Dash as a bonus action.

Mark. As a bonus action the Auxilia can mark a target. The target receives an additional d6 damage from successful attacks made against it by this or other allied Auxilia. Additionally, the Auxilia has an additional d6 added to saving throws from attacks made by the marked target.

Spellcasting. The Auxilia is a 10th-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 16, +8 to hit with spell attacks). The Auxilia has following Ranger spells prepared:
1st level (4 slots): Protection from Evil and Good, Cure Wounds, Hunter's Mark, Fog Cloud,  Ensnaring Strike
2nd level (3 slots): Zone of Truth, Silence
3rd level (3 slots): Magic Circle, Flame Arrows

Multiattack. The Auxilia makes two attacks with its repeating crossbow, or two with its rapier.  

Rapier. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 10 (1d8 + 5) piercing damage. 

Repeating Crossbow. Ranged Weapon Attack: +11 to hit, range 80 / 320 ft., one target. Hit: 6 (1d10) piercing damage.