Naizu-Ha 2014

Each creature that deals piercing or slashing damage with a bladed weapon while within 30 feet of the naizu-ha must roll the damage twice and take the lower result.

As a bonus action, the naizu-ha transforms into a magical dagger. A creature that wields the naizu-ha while it is in this form gains +1 bonus to attack and damage rolls with the dagger, and attacks with the dagger score a critical hit on a roll of 19 or 20. In addition, the wielder can’t take the Disengage action unless it succeeds on a DC 12 Wisdom saving throw.

The naizu-ha can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

If the naizu-ha moves at least 15 feet straight toward a creature and then hits it with a scythe tail attack on the same turn, that target must succeed on a DC 14 Dexterity saving throw or be knocked prone. If the target is prone, the naizu-ha can make one dagger legs attack against it as a bonus action.