Incorporeal Movement. The akikage can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.
Sunlight Sensitivity. While in sunlight, the akikage has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.
Multiattack. The akikage makes four unarmed strikes.
Unarmed Strike. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 10 (1d6 + 4) cold damage.
Death Blow. The akikage becomes visible for one round, channeling its power into a devastating strike. The target must make a DC 15 Constitution saving throw, taking 21 (6d6) cold damage on a failed save, or half as much damage on a successful one. Additionally, if the target fails a DC 15 Constitution saving throw, it dies instantly, regardless of its current hit points. If the target dies, its heart is frozen solid. The akikage can't use this ability again until it finishes a long rest.
Invisibility. The akikage can become invisible. Any equipment the akikage wears or carries is invisible with it.
Shadow Stealth. While in dim light or darkness, the akikage can take the Hide action.
Evasion. When the akikage is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.
Legendary Resistance (3/Day). If the akikage fails a saving throw, it can choose to succeed instead.