I've never heard of this before. I did a bit of digging and it turns out that this is an OD&D compatible campaign setting, that was published last year.
Here is the blurb:
Has anyone got this? What do you think of it?Yoon-Suin is a campaign toolbox for fantasy games, giving you the equipment necessary to run a sandbox campaign in your own Yoon-Suin - a region of high adventure shrouded in ancient mysteries, opium smoke, great luxury and opulent cruelty.
- A bestiary of unique monsters, including self-mummified monks, liquid golems, tiger-beetle men, figments, and dozens more
- A new character class, the Crab-man
- A chapter for each of the major regions of Yoon-Suin, filled with random generators to brainstorm map contents, social groups, and more
- Extended rules for poisons, tea, opium, trade, deities and so on
- Extended rules for exploring the Old Town of the Yellow City, and the haunted jungles of Lahag
- Many encounter tables
- Well over 100 pre-written adventure locales to populate a regional map
- Over 300 pages of content
- Purple prose
How easy would it be to convert use the chapters of the regions of Yoon-Suin with a ruleset other than OD&D?
I can imagine why someone might want rules for poisons, but what do the rules for tea do?