The KT-4 wonder weapon was already an outstanding weapon against the creatures of the forest of Zetsubou No Shima but if you want to go for higher rounds then the Shima Masamune upgrade for the weapon should do the trick in BO3 zombies.
The Shima Masamune weapons upgrade is not only good for obliterating the thrashers but it serves a bigger purpose in zombies as it helps to unlock a secret passageway to more Perk-a-Colas for you to have and leads to the final boss battle in the Easter Egg.
The process for the upgrade is the same as collecting the parts for the buildable items but with some extra steps. To help you get the Shima Masamune upgrade during the first few rounds of the game, read the guide below.
How to get the Shima Masamune upgrade in Zetsubou No Shima
To get the Shima Masamune upgrade, players will be required to get three parts around the map. The parts include a yellow liquid, a green liquid, and a blue plant. All three of these items require some sort of leg work to be done.
Shima Masamune Part 1
To get a hold of the yellow liquid, players must first complete all of the challenges at the Nan Sapwe altar to get the upgraded electric shield. Once the shield has been acquired, simply head on over to Lab B and hit the console command for the cage to open it. Enter inside the cage and ask one of your teammates to interact with the terminal to close the cage.
Once the cage closes, it’ll take you to an underground area. While still in the cage look for a skull holding the yellow liquid. Simply press square to acquire the item.
Shima Masamune Part 2
For the green liquid, you’ll be required to kill the spider boss in the hidden lair inside Lab A. Simply use the KT-4 wonder weapon to melt the webbing in that leads to a cave with the spider boss. Defeat the large insect and then crawl into its corpse to obtain the second item.
Shima Masamune Part 3
The last item can be found by acquiring the golden bucket inside the sewer pipes. To get the golden bucket, you must have the regular bucket equipped and launch yourself through the sewer pipes.
Look towards your right to spot three 115 blue rocks. Time yourself with the rocks and press square as soon as they appear to get a hold of the golden bucket.
After the bucket is acquired, simply head on over to the same underwater area across the Mule Kick Perk-A-Cola where you will find the red plant for the wonder weapon in the Main Bunker.
Swim down there and use the Nan of Sapwe skull to mesmerize the eastern wall. The wall will break off and a mud dug will appear. Plant a seed in there and water it with the iridescent water for three consecutive rounds to acquire the blue plant.
How to build the Shima Masamune
Once all three items are with you, simply head to the workbench where the KT-4 wonder weapon was created. Next to the original workbench will be another identical workbench, place all of your ingredients there including the original wonder weapon to get the Shima Masamune upgrade in Zetsubou No Shima.
