Reliving that quest gave me some time to think of revising it, & I think there may be thoughts I'm thinking of.

Once I entered the Imperial Garrison with the Imperial Standard purified by Brother Xian Bhi, I see Isao Murasaki, but there already is one, from the side quest, "The Bushi Brothers", so I think it's odd to face him as a main quest boss & a side quest boss, so I think that boss from that main quest should be replaced with a new opponent to take his place & Isao would remain as that side quest's boss.

I think his name would be Mooto Moosano. Plus, that replaced boss should have dialogue before we face him in battle. I think it should be this...

Mooto Moosano: "Vile Amber Horde barbarians! You have troubled our sacred lands for the last time! No more! You destroyed our village, and now, your rampage ends in yours and Hunan's death! End them!"

This dialogue addition should reflect the Samoorai ghosts' suffering from the Amber Horde & under the magic's enchantments that made them think the Amber Horde and Hunan were in that place.

Those are my thoughts on changing that quest. I would think having a different opponent in that quest would be a bit more original. What do you think, Pirates? KI, I hope you may do these changes someday.