Keen sight.

Yatagarasu has advantage on Wisdom (Perception) checks that rely on sight.

Necrotic Shroud.

Chosen creatures within 30 feet of yatagarasu that it can see must each succeed on a constitution saving throw (DC 8 + your proficiency bonus + your Con modifier) or become frightened of you, once on each of your turns, you can deal extra necrotic damage to one target when you deal damage to it with an attack. The extra necrotic damage equals 2d8.

Multiattack. The Yatagarasu makes two attacks: one with its beak and one with its talons.

Beak. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 27 (4d8 + 9) piercing damage.

Talons. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 23 (5d6 + 9) slashing damage, and the target is grappled (escape DC 19). Until this grapple ends, the target is restrained, and the roc can't use its talons on another target.