Mystic Rings. The Yaonachi's serrated dao has 6 golden rings with runic symbols engraved in them. When the Yaonachi lands a melee attack with the dao, they may have one of the rings appear on the target. The Yaonachi can detonate the rings power to deal an additional 1d10 force damage, the uses of these rings can be stacked onto one singular target. All expended uses of these rings are regained upon a long rest.

Aberrant Sight. The Yaonachi can see through magical and nonmagical darkness.

Spellcasting. The Yaonachi is a 7-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 17, +9 to hit with spell attacks). The Yaonachi has following Wizard spells prepared:

Cantrips (at will): booming blade, toll the dead, fire bolt, chill touch
1st level (4 slots)burning hands, magic missile, frost fingers
2nd level (3 slots) blur, misty step
3rd level (3 slots) haste, lightning bolt
4th level (1 slot) vitriolic sphere

Multiattack. The Yaonachi can make three longsword attacks or three automatic crossbow attacks.

Mystic Serrated Dao. Melee Weapon Attack: +11 to hit, reach 5 ft., 1 target. Hit: 18 (2d10 + 6) magical [slashing] damage.

Automatic Crossbow. Ranged Weapon Attack: +11 to hit, range 100/200 ft., 1 target. Hit: 17 (2d8 + 6)magical [piercing] damage plus 9 (2d6) [force] damage.

Cantrip. The Yaonachi casts a cantrip.

Cast Spell. The Yaonachi casts a spell.

Dash. The Yaonachi can dash as a bonus action, doubling their walking speed. 

Precise Accuracy. The Yaonachi can use a bonus action to give themselves advantage on attack rolls until the start of their next turn. In turn, their armor class decreases by 5. 

Parry. When the Yaonachi is hit by an attack, they can add +5 to their Armor Class, potentially making the attack miss.

Riposte. When the Yaonachi is hit by an attack, they can use their reaction to make a melee or ranged attack in return.