The instructor of siege engineering and construction at the Winter Academy.
BUT ALSO THE NAME OF ONE(ish) OF THE LAST GENERATION OF THE MARKED.
According to Elder Danyu:
"The most interesting thing about Huan Ken is that there were two men of that name, who worked together. Twins, one a talented architect, one a powerful [earth] sorceror. They were not given the same name by their parents, but took the same true professional name and consulted together on their greatest works."
The two men died at nearly the same time, in the different cities they lived in, though that would not be surprising, given the significant amount that they had bound their lives together. A list of buildings and works devised and developed by Huan Ken includes the Coil, but also works in most other countries of the Empire.
"Stone Upon Stone" is a little book written by Huan Ken explaining various principles of architecture.
Master Zhou is somewhat obsessed with Huan Ken.