KT-4

The KT-4, also known as the Kusanagi-no-Tsurugi, is a buildable Wonder Weapon that appears in the map Zetsubou No Shima, and is key for many mechanics featured on the map. This weapon fires a green liquid that causes spore bags to grow on standard zombies before exploding. Shots can be charged up to three times, which causes the liquid to remain on the floor, bubbling and affecting any zombie that goes over it. This charge can be cancelled by meleeing. 
Notably, it is very effective against Thrashers, causing their weakspots to break and potentially killing them outright when fully charged. It also instantly explodes small Spiders as well as any webs they create blocking passages or covering Perk/GobbleGum Machines. 
This weapon also affects the various flora of the map, with the projectile acting as fertiliser for the Seeds, which is key for Seeds of Doubt during the anti-air cannon flak shell step. It has an upgraded form, the Masamune, also used in the final step. 
If shot at the yellow-orange toxic spores found on various walls throughout the map, the negative effects of coughing (inability to fire weapons, no sprinting) will be reversed. Instead, the created blue spore clouds will temporarily increase movement speed along with increased sprint duration with a temporary immunity to all spore clouds, after which the player must recover their full sprint duration. This can be chained once the initial effect ends with no cooldown if there is another spore to shoot nearby. Thrashers killed by this weapon will spawn these special blue spore clouds as well.
==Obtaining==
===KT-4===
The KT-4 can be found in the Bunker but requires unique ammo that needs three ingredients to be crafted. The ingredients are:
	A randomly spawned scientist zombie will be glowing a sickly yellow/green and will drop the vial secured on its hip upon death. The vial also glows a bright yellow-green when it drops on the floor.
This zombie will only spawn after the main Power Switch is turned on in the Bunker, and tends to first spawn at/under Lab B. Begin rounds with at least one player at the Lab B side of the map, and it should appear within a few rounds.
	Within Lab A, if the power is restored there is a cage that can be lowered down into the swamp below, doing so will open it up, revealing an arm that is producing a purple mist. This can be used to trap a Spider in by luring one close to the cage. With a spider in the cage, returning the cage back up to the lab will cause a nearby syringe to extract a vial of venom from the spider, killing it in the process.
If this was done on the last Spider of a Spider round, the Max Ammo will spawn inside the cage. The cage must be lowered again to obtain the Max Ammo in this scenario.
	Located in the flooded section of the Bunker Laboratory to the right of Mule Kick at the very end of a tunnel of raw Divinium. There are pockets of air to resurface to in the first half and spores which can be shot for additional time underwater, as this is quite deep to get to and return from.
This is deeper in the same tunnel as the Turn Wheel part for draining the water around the Pack-a-Punch machine spawns. The Turn Wheel spawns in the first half before the "drop off" in the tunnel changes the walls colors to resemble Divinium.
With the ingredients in tow, they can be mixed in the KT-4 bench, allowing the KT-4 to be picked up and to start spawning in the Mystery Box. Multiple players in the game can have the KT-4, the player who crafted it does not need to get rid of it for it to be available in the Box.
===Masamune===
The KT-4 cannot be upgraded via the Pack-a-Punch Machine, but requires a more potent ammo to be crafted on a different bench located in the same room of the Bunker to be upgraded. It gains a much improved chaining effect against enemies when fully charged, and is necessary for the final step of the Easter Egg.
* None of these ingredients have visible pickup icons unlike the KT-4's ingredients, only character dialogue once picked up.
* None of these ingredients are obtainable unless the KT-4 has been acquired first. 
	The Zombie Shield must first be electrified from being struck by lightning hitting the Trials of the Ancients altar, which only occurs after all players in the game have completed all 3 of their trials. This lightning strikes periodically (not tied to once a round). 
The cage within Lab B can then be opened by meleeing the control panel. Entering the cage from inside Lab B will lower the cage down into the swamp before opening up the panels below, revealing a small area that houses multiple skeletons, one which is holding a vial of Liquid Divinium. In co-op, the console must be electrified to open the cage, then electrified by another player to lower it into the ground. After obtaining the vial, the player who lowered the person in the cage must press the console (not necessary to electrify again) to raise them back up.
	Upon killing the Giant Spider located in the cave initially covered in webs behind the Blue water pool near Lab A by clearing them with the KT-4, the fang can be removed by interacting with the corpse.
	This plant requires several steps to obtain, and only blooms after successfully building the KT-4. The Skull of Nan Sapwe Mesmerize ability must first be used on the torn blueprint paper in the Living Quarters located in the Bunker, in the same part of the Living Quarters as the Purple water pool that can fill the Bucket. Mesmerize must then be used again on the right wall beside where the original plant was underwater to reveal a hidden Seed planter, where this plant must be grown. The plant must be watered three times over three rounds to sprout the unique plant. However, this plant also needs a unique type of water to feed it. This special iridescent water is located within the Sewer Pipe fast travel, obtained from a small Divinium meteorite on the right side. 
The most consistent way to obtain this water is by taking the Sewer Pipe in the direction starting from the back of the Bunker exiting out towards behind Lab B, and waiting to press Use once the player fully passes through the second blue section in the Pipe.
After obtaining all 3 ingredients, these can be processed on the second bench on the back wall next to the original KT-4 Bench to create the blue ammo that converts the KT-4 to the Masamune. Players can only interact with this new workbench if they have the KT-4 as the active weapon held.
==KT-4 vs Masamune==
==Gallery==
KT-4 BO3.png|First person view of the KT-4
KT-4 Sights BO3.png|Aiming down the sights of the KT-4
KT-4 Reload BO3.png|Reloading the KT-4
KT-4 Parts Zetsubou No Shima BOIII.jpg|The parts to craft the KT-4.
Obtaining the Spider Serum BO3.png|The serum needed to craft the KT-4 being taken from a Spider.
Creating the KT-4 1 BO3.png
KT-4 Ingredients BO3.png
Creating the KT-4 2 BO3.png|Richtofen observing the finished KT-4
KT-4 Side View BO3.png
KT-4 Outline Chronicles Drawing BO3.png|A drawing of the outline of the KT-4 as seen in the Zombies Chronicles timeline poster.
==Achievements/Trophies== 
*Seeds of Doubt (75/Silver Trophy) - In Zetsubou No Shima, the one must be saved.
*Herbal Remedy (20/Bronze Trophy) - In Zetsubou No Shima, use a plant to return to life.
*Crop Duster (15/Bronze Trophy) - In Zetsubou No Shima, kill 10 zombies with a single shot of the KT-4.
*Web of Defeat (5/Bronze Trophy) - In Zetsubou No Shima, remove webs in every possible way in one game.
==Trivia==
*The full name of the weapon, Kusanagi-no-Tsurugi, is also known as the name of a legendary Japanese sword, one of the three Imperial Regalia of Japan. Its upgraded form, the Masamune, is also the name of a legendary Japanese swordsmith.
* On the side of the KT-4, there reads "731細菌戦の研究機関", roughly translating to "Research Institution 731 of Bacterial Warfare". This is a reference to Unit 731, a Japanese covert research group on whom Division 9 is based.
*The KT-4's serial number is 02182016 and Masamune's is 03182016.
==References==
Category:Call of Duty: Black Ops III Wonder Weapons
Category:Call of Duty: Black Ops III Zombies Buildables