Experimenting with the extreme negative constraints, this feels like it's actually quite easy (1/5), though i did struggle to remember disjoint set restrictions, even while setting.
Rules are as follows:
- Normal Sudoku rules apply. Place the digits 1 through 9 in each empty cell. Digits must not repeat within the same row, column, or box.
- Digits must not repeat at corresponding box positions. (Disjoin set)
- Digits must not repeat in cells that are a chess king's move apart.
- Digits must not repeat in cells that are a chess knight's move apart.
- Orthogonally adjacent cells must not contain consecutive digits.
***From feedback, it turns out the disjoint set constraint is not actually necessary.
CTC:
https://tinyurl.com/DoggoExperiment4
f-puzzles:
https://f-puzzles.com/?id=2h8erqpt

Solution code: The digits from column 1, in order, from top to bottom, and the digits along row 9 from left to right, with no spaces or punctuation
Last changed on on 2. May 2023, 05:27
Solved by nmmc123, pjhiatt, Greg, thrutch, fattysalsa, gonzalez87, jguer, Cypher, rictech, Ximota, flaemmchen, cathematician, belfieldtj, slowbiex, Miaocik, NeroChaos, Matti64, zrbakhtiar, asver, T1geR, ... Thomster, rhodri, Felis_Timon, forsen, radium, dingledork, jalebc, Isfan, pms_headache, ellamackmitch, elpizw, drifting, Lodinn, Meghan29, Fesius, bhambells, elloschmello, renegade_duck, Jagson
Comments
on 4. May 2023, 21:10 by wentel21
I agree, no need of disjoint set rules. nice puzzle Thx!
on 2. May 2023, 05:27 by waffles_the_dog
immediately broke the html description
on 2. May 2023, 05:26 by waffles_the_dog
Added a note on the disjoint set constraint being unnecessary, removed the tag for such.
I assume I broke the requirement for disjoint sets while trying to ensure a non-bifurcation path existed.