Follow this guide to quickly ( hopefully ) farm all the materials you need
Weapons : Any Nameless sword that has good armor penetration ( I am using Okanehira in the video ) + Good damage pistol ( Basically anything crafted, like Dragon Hawk/Model 14/Vortex )
Important : You need to have the exact same Kasuga in both Wild Dancer setup and Gunmen. Wild dancer also requires Ishioda+Yonashido+Rikiya to get rid of soldiers.
FAQ: You basically start with Wild Dancer, shred the armor off every unit and then continue to hit Sanada until you have troopers ready = you activate all of them except for Kasuga and obliterate the trash, then you switch to Gunmen – pop Kasuga – use your RT move to finish off the boss