Instead, a very similar yet different variation – 4 puzzles in an X-Ring. This is not to be confused with the X-Wing solving technique!
X-Ring for Saturday, December 03 – this is the only place you can find these kind of Sudoku puzzles!
Basically, not only do you have to fight against 4 interconnected Sudokus, but you also need to be carefull about the diagonals: ALL diagonals in the puzzle must contain one occurrence of each 1-9 digit. The diagonals are marked in the puzzle so you wouldn’t forget about them.