Li the Wanderer
We still don't have a lot of information on the eighth marked. We don't remember what we found out from the Butterfly King in the world above, except that nobody will believe it, and whoever that particular Marked is, it's probably responsible for the lack of memory in the Empire about the changes that are happening.
It seems that in the past, Li was a Dragon, whose stories were told far and wide. Xian speculates that he is the Remarkable Wanderer of the Book of the Remarkable Wanderer, Hiro's elven rope from Ti Wren.