Charon, Captain of the Kiyohime

Opportunistic. Charon can trigger attack of opportunity on enemies who are retreating from him. 

Spellcasting. [Charon, Captain of the Kiyohime] is a 1st-level spellcaster. Its spellcasting ability is [12] (spell save DC 11, +3 to hit with spell attacks). [Charon, Captain of the Kiyohime] has following [Druid] spells prepared:
Cantrips (at will): [Produce Flame], [Control Flames] 
1st level (2 slots): [Earth Tremor], [Thunderwave] 

MultiAttack. Charon can perform two attack actions per turn.

Cutlass Slash. Melee Weapon Attack: +3 to hit, reach 5 ft., 1 target. Hit: 12 (1d4 + 5) [Slashing] damage. 

Blunderbuss Shot. Ranged Weapon Attack: +2 to hit, range 20 ft., 1 target. Hit: 12 (2d6 + 4) [Piercing] damage.

Charon can use his bonus action to cast the 2nd level spell Flame Blade. 

Flame Blade.

You evoke a fiery blade in your free hand. The blade is similar in size and shape to a scimitar, and it lasts for the duration. If you let go of the blade, it disappears, but you can evoke the blade again as a bonus action.

You can use your action to make a melee spell attack with the fiery blade. On a hit, the target takes 3d6 fire damage.

The flaming blade sheds bright light in a 10-foot radius and dim light for an additional 10 feet.

This effect lasts for 10 minutes, and uses melee attack/saves.

Attack of Opportunity. Anyone moving through Charon's position or away from him can be attacked by his cutlass.