Hessi

Hessi is the author of Mythica, which is a volume focused on the history of the Unmade, attributing to each of them distinct personalities.
According to Shallan, Mythica is a newer book, and has been poorly received. Further, that it claims there were nine Unmade, which matches a vision that Dalinar saw.
The book claims the nine rampaged during the Desolations, but says not all were destroyed at Aharietiam. The author insists that some remain active today.
Again, according to Shallan, the book says nothing about fighting them. But it does say that if one sees a spren the wrong color, one is supposed to immediately move to another town.
Further, she says that Hessi reports stories of the Unmade not only corrupting spren, but corrupting people.
Still further, according to Hessi, each of the Unmade has a dozen names, and the powers ascribed to them range from the fanciful to the terrifying.
==Speculation==
There are those (i.e., Isilel) who have theorized that Hessi is actually a Herald in disguise. (See Oathbringer Reread on tor.com here.)
==References==
Category:Historical People
Category:Author