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

Brine Lurker. The deep diver has advantage on Dexterity (Stealth) checks made while submerged in water.

Limited Amphibiousness. The deep diver can breathe air and water, but it needs to be submerged at least once every 4 hours to avoid suffocating.

Lure. The deep diver can cause its lure to light up or darken at will. While the lure is lit, the deep diver sheds bright light in a 30-foot radius centered on itself and dim light for an additional 20 feet.

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

Multiattack. The deep diver makes two attacks with its glaive, or one attack with its bite and two with its claws.

Glaive. Melee Weapon Attack: +4 to hit, reach 10 ft., one target. Hit:13 (2d10 + 2) slashing damage.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit:7 (1d10 + 2) piercing damage.

Claws. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit:6 (1d8 + 2) slashing damage.

Light of Sekolah. The deep diver pulses magical light from its lure. Any creature within 30 feet of the deep diver that can see the light must succeed on a DC 11 Wisdom saving throw or be charmed until the end of its next turn. A creature charmed in this way is incapacitated as it stares at the light.