Joshor is the head of King Taravangian's Silent Gatherers. He is the author of the letter in the Endnote of The Way of Kings, believed to have been sent to Taravangian. In it, he explained the poetic form of a dying man's words to his majesty.
In other words, when people die, it is believed that they speak some sort of prophesy. This man is gathering these words and analysing them. These words are known as death rattles.
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