Cee-Korel, the Mighty Sahuagin Lich

Legendary Resistance (1/Day). If the sahuagin fails a saving throw, it can choose to succeed instead.

Blood Frenzy. The sahuagin has advantage on melee attack rolls against any creature that doesn't have all its hit points.

Amphibious. The sahuagin can breathe air and water.

Shark Telepathy. The sahuagin can magically command any shark within 120 feet of it, using a limited telepathy.

Rejuvenation. If it has a phylactery, the sahuagin gains a new body in 1d6 days, regaining all its hit points and becoming active again. The new body appears within 5 feet of the phylactery.

Turn Resistance. The sahuagin has advantage on saving throws against any effect that turns undead.

Spellcasting. The sahuagin is an 5th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 14, +6 to hit with spell attacks). The sahuagin has the following spells prepared:

Cantrips (at will): chill touch, frostbite, mage hand, poison Spray

1st level (4 slots): false life, magic missile, armor of agathys, inflict wounds, disguise self

2nd level (3 slots): mirror image, ray of enfeeblement, enlarge/reduce, darkness

3rd level (2 slots): animate dead, bestow curse

Multiattack. The sahuagin makes two melee attacks: one with its bite and one with its claws.

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

Paralyzing Claws. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 4 (1d4 + 2) slashing damage. The target must succeed on a DC 14 Constitution saving throw or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

The sahuagin 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 sahuagin regains spent legendary actions at the start of its turn.

Fear my Magics! The sahuagin casts a cantrip.

I'll Save you for Later! (Costs 2 Actions) The sahuagin uses its Paralyzing Claws.

Here's the Spooky Look! (Costs 3 Actions) The sahuagin fixes its gaze on one creature it can see within 10 feet of it. The target must succeed on a DC 14 Wisdom saving throw against this magic or become frightened for 1 minute. The frightened target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a target's saving throw is successful or the effect ends for it, the target is immune to the sahuagin's gaze for the next 24 hours.