I'm a little bit confused by the blackened cells. Their coloring seems to tell me to use them in more than one grid. What do I do with black cells in a Sudoku or Four-Winds-puzzle?

The cells without numbers are for the answer extraction. Ignore them until you have the three grids filled.

This was a great combo of classics. Loved the way you had the solver jumping back and forth so much to each one to work out the opportunities or constraints. Enjoyed it greatly once I got my feet on the ground as to the rules, and then figured out which of the three must be which of the varieties. Have no idea whatsoever about the colored boxes or what they mean (if anything) as an additional solution, but I am at peace with that.

Thanks for thinking of us masses even though you were bogged down in a foreign land with no air conditioning or rest.

p.s. Been spending wonderful time with "Mutant Sudoku." What a gift to all of us fans!

Ken

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How many could have created it?
... how many could have solved it?
How wonderful for both.

p.p.s. Does anyone find it ironic that the spellcheck on this blog-site does not recognize the word Sudoku?

Great work. Also managed to decode the colored squares in the center. Progress was slow until a massive breakin in the Four Winds puzzle, which I'm sure you intended to happen. After that it was mostly figuring out the black clues in the center.

Also, I just noticed the 1-9 restriction... that can apparently be replaced by 1-anything and the puzzle still works (although requiring that sudoku is always 1-9).

Yeah, I see I had that constraint at the top now too (its been a year since I've thought about these three) - not really needed here I guess but it makes the 26 clue a faster start.