Sword, lance, two shields, clothing
The Zero-Type Izayoi is the evolved form of the Sealed Weapon Izayoi. While the Sealed Weapon can be described as a shield, the Zero-Type is a lance that can kill most immortals. It is a prototype of the Lux Sanctus: Murakumo.
The abilities of the Zero-Type are similar to its pupal form, the Sealed Weapon. It can deploy a Zanki Barrier, or at least maintain one between changing forms. It is still a weapon designed to counter Observers, but ironically was only able to be used by Tsubaki Yayoi after it was Observed by Noel Vermillion. Tsubaki is the only known wielder of the weapon, as not even Ayame Yayoi was able to achieve the evolved form.
One of the most important abilities of the Izayoi is that it possesses the Immortal Breaker, which allows it to kill beings that are not only considered immortal, but also exist outside of Logic itself. While it can kill individuals such as Rachel Alucard, the Immortal Breaker is not capable of killing certain individuals, such as Jin Kisaragi and Hakumen (because of Order) , and Izanami, who is a Drive. 
In terms of appearance, Izayoi has a large sword with a thin handle and thick pommel; the blade itself is angular and rose pink. There are two shields that constantly follow the wielder, but they can open up to reveal bladed openings that can be used for battle. As well as this, when they open up, they can be used for short bursts of flight, leaving behind green streams of energy. There exists a mode for Izayoi which has a large shield with a lance within it that can be drawn - Tsubaki uses this for both transport and her Astral Heat.
The location of Tsubaki's Izayoi is currently unknown. It is possible for the user to slip back and forth between either the Zero-Type or Sealed Weapon variants.
The true form of the 'Sealed Weapon Izayoi.'
While the 'Sealed Weapon Izayoi' is a 'shield' capable of warding off intervention, the 'Zero-Type Izayoi' is a 'lance' with the power of the 'Immortal Breaker.'
By forcing its target to recognize their own 'death', it is capable of 'killing' even those 'outside of reason' such as Rachel. However, it is incapable of piercing those with the 'Power of Order' such as Jin.
Izayoi (十六夜) is short for 十六夜の月 izayoi no tsuki (lit. "moon of the sixteenth night"), the first moon after a full moon and the start of the waning moon, or when the moon begins to lose its brightness. This naming is likely in reference to the Izayoi's pupal form's ability to steal light from its wielder.
- BlazBlue: Chrono Phantasma, Story Mode, Episode 14
- BlazBlue: Central Fiction, Arcade Mode, Izayoi, Act II
- BlazBlue: Central Fiction, Library Mode, Weapon #018