Basho found

The next few days passed with no leads... then a message came from Tacitus the Scholar.

Asoka forgets that we Alluvians are knowledgeable, as well. You need not take the letter from this Gharun cultist to the Hebian To library. We at the Cragstone library have studied the text, made available in these archives and in Kikuchi Kentaro's papers, and we can arrive at no other conclusion than what follows.

Basho Genji is being held by a cult known among the Gharun sultans of Ispar as the Chakari. (This is not a word of Gharun origin. We cannot divine its meaning, or its source.) It must be so, for this cult alone wields control over the undead that this group in Dereth seems to have. 

They are great workers of death. They are capable of summoning the type of demon that plagued your group months ago. (See the archives here.) They, as well, would likely have the ability to "cancel" one's connection to a lifestone, resulting in permanent death. (I grieve for Murasaki Tanka, though I know him only from the history books. I believe, however, that he was the "item from Ispar" that Basho Genji wished for me to see.) 

But you of Jojii's Sword have also shown that the undead, particularly the lich lords, may indeed work the strings that pull this cult toward a greater agenda. The altar in Grievous Vault, and the presence of a powerful lich lord there, shows that they worship a force more cunning and evil than the greed of a fat Sho merchant king. 

(As Basho Genji has said, this cult was most likely hired by the greedy Lord Yoshioka Tempo, of Ispar, when Murasaki Tanka refused to train his troops for war against my people. Why the Sho lord did not trust such a mission to the formidable assassins under his employ, I do not know. As I have said, there must be a greater agenda than mere revenge.)

Little is known about the extent of the Chakari's infiltration of Dereth. We may gather the following. First, they have have from time to time used Uziz a base of operations. The altar in the mage shop there attests to this. The importance of the painting above that altar remains unknown. Second, they have occupied at various times the abandoned outpost above Shoushi. Interestingly enough, that place is littered with strange paintings. Finally, we know that they are connected to a lich lord in the Grievous Vault. Kikuchi Kentaro can attest to this, as well as to their connection to the place called Thasali.

I will add the following, and thus give you to key to unlocking Basho Genji. We know the Chakari to control a place called Enkindled Souls, a
dungeon outside of Khayyaban. It sits in the mountains above that small Gharun settlement, at 49.4S, 26.9E. One must be of at least level 8 to enter, though it bars none higher than that. 

 We believe Basho Genji to be held there, as the Gharun of Khayyaban, who are mostly trustworthy, unlike those of Uziz, speak of strange activity. Many even claim to have seen a Sho warrior, bound and blindfolded, being led by a cohort of skeleton captains in and out of this cavern at various times.

We know not why this captive would be moved so often. Nor do we know where they take him, for the trail is always lost among the jagged rocks. Some say that he is moved in and out of the Shadow Spire of Khayyaban, but none can verify that. In any event, we believe him to be your lord,
Basho Genji.

Basho can be found!  Excitement flowed through everyone, as a chance to save their dear friend appeared.  Warriors both young and old - Pew the Mottled, Ma Zhirui, Kikuchi Kentaro, and Arlorn - rushed to the deserts, weapons ready to crush whatever might interfere.  With great stealth, they passed through the town of Khayyaban undetected and headed to Enkindled Souls.  Skeletons, Zombies, and even a few Liches were dispatched quickly.  Deep in the dungeon they came across a familiar figure.

It was Basho, in a tortured state.  Welts covered him, and blood dripped slowly from his mouth.  The rescuers tended to his wounds, and after a few moments, he spoke.  "Where is Murasaki?" were the first words he spoke.  And the faces of those around him told Basho what had happened.  "There is one thing I must do before I leave...exact revenge on the Lich who tortured me."  With that, he took up his sword and dispatched his former jailer with great fury.  The adventurers fought their way out of the crypt, alerted undead rushing to meet them.  After some time, they breathed fresh air again in the setting sun.

The adventurers rest after the ordeal

Resting outside, it seemed that all was safe for the moment.  Basho's followers were ready to return to Lin, when he said, "I am not returning yet... I will walk the deserts for a while, and talk to my teacher."  Despite all of their protestations, Basho would not relent.  He did indeed seek out some peace of mind, only returning to Sho lands after he was ready.

When he returned, A ceremony was held for the deceased Murasaki Tanka.  While few knew him as Basho did, all who attended honored his passing.