Blue Darakhon

Legendary Resistance (3/day). If the Darakhon fails a saving throw, it can choose to succeed instead.

Multiattack. The Darakhon makes two attacks, one with its greatsword and one with its bite.

Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) piercing damage and the target is grappled (escape DC 17). Until this grapple ends, the Darakhon can't bite another target. 

Greatsword. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 19 (4d6 + 5) slashing damage.

Magnificent Presence. Each creature of the Darakhon's choice that is within 90 feet of the Darakhon and aware of it must succeed on a DC 16 Wisdom saving throw or become frightened or charmed by it (the Darakhon's choice) for 1 minute. A creature can repeat the saving throw is successful or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.

Lightning Breath (Recharge 5/6). The Darakhon exhales lightning in a 60-foot line that is 5 feet wide. Each creature in that line must make a DC 17 Dexterity saving throw, taking 33(6d10) lightning damage on a failed save, or half as much on a successful one.

The Darakhon can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The Darakhon regains spent legendary actions at the start of its turn.

Detect. The Darakhon makes a Wisdom (Perception) check.

Greatsword Attack. The Darakhon makes a greatsword attack.

Magnificent Presence. The Darakhon uses its magnificent presence action.