Tamer Karatekin has composed a harder version of the Suli's Diamond endgame study.
Look also at his presentation at YouTube!
Beware the rules in this article are the old form of chess (shatranj).
For these rules see: https://ancientchess.com/page/play-shatranj.htm
Because the PGN-tool at this website can't show you the moves, I give you the diagrams where a FEN is in the article:
Below the article with all the details:
See also: https://doi.org/10.5281/zenodo.19465731
Suli_Karatekin_Diamonds_Reverse_Ferz_40_positions
If you have an iOS device (iPad or iPhone), browsing the PDF file will not work properly,