Aeli

Opportunist. When Aeli avoids damage by AC granted by parrying, he will perform a special unarmed attack. The target must make a Constitution saving throw after taking 1d4+2 damage. On a failed roll, the target is stunned for one turn. If the target succeeds, the monster will take 1d4+2 damage.

Guards. When the players begin the encounter with Aeli, he sits in his throne and does not get out until both of the 2 royal guards in the throne room are dead. When 2 or more guards are in combat, he will deflect all physical attacks, taking only 1 damage per attack, and will absorb all force/magic damage, healing him 2d4 damage

Multiattack. Aeli makes two halberd attacks. If his sword is drawn, he makes two shortsword attacks and finishes with a magic kick that does no damage but knocks 

Halberd. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit:  1d10+2 slashing damage.

Shortsword. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 1d6+2  piercing damage.

Warrior's Fire breath. Aeli will leap 20 ft in any direction and will use a unique version of his breath weapon. This breath weapon has a 15 ft long 5ft wide range. . Each creature in that area must make a DC 15 Constitution saving throw, taking 3d6 fire damage and causing the frightened status effect on a failed save, but on a successful save causes frightened status.

Parry. Aeli switches to a defensive stance. +2 AC.