Finished stage 3 Kusanagi last weekend and finally got to toy around with it. Good lord Mumei is a good weapon skill, even without Aria last night (just ran with trusts on an off night) it was consistently doing about 20k more than MasaFudos, often damage capping without real bard buffs which felt insane to someone who isn't an avid Savage Blade enjoyer.
How do I best utilize it? It feels like a lot of fights are very much not friendly with the skillchain properties it has and I'm okay going back to Masamune and Dojikiri for the fights where it clearly isn't a safe option. That being said, I just spent a few weeks getting this sword so I want to use it as much as possible. Right now our core group is SAM BRD WHM RDM COR and we fill the last spot with either a GEO or a random Savage Blade-r. It will very likely be the weapon I attempt to stage 5 even though Samurai isn't particularly useful for Aminon.
I full timed Kusa in Sortie for the short time I was able to go SAM. Put up AM then spam the correct WS for the boss. D/H you want to use Mumei or Fudo depending on the mode. The other 6 bosses you can just spam the correct WS.
A/E Kagero
B/F Mumei
C/G Koki or Fudo
D/H Depends on mode
Yaegasumi was best for F but also great for H if you can use it twice in a run.
Does anyone else think the Pink glow is much more pronounced in Windy?