Logic Masters Deutschland e.V.

This is my first attempt at creating a challenging sudoku. It's far enough above my own skill that I was forced to do a quite a bit of bifurcation to complete it, but I suspect that more advanced solvers will be able to complete the puzzle without resorting to such uncivilized behavior :) As always, feedback is welcomed and encouraged, so please let me know how you got on in the comments below.

• Normal Sudoku Rules: Fill each row, column, and 3x3 box with the digits 1-9 once each.
• Quadruple Circles: Digits in a circle must be appear at least once in the four cells surrounding the circle.
• Positive Diagonal/Negative Diagonal: Digits along the positive diagonal (R9C1 to R1C9) must be unique. Digits along the negative diagonal (R1C1 to R9C9) must be unique.
• Nonconsecutive: Orthogonally adjacent cells cannot hold consecutive digits.
• X: Cells separated by X must sum to 10.

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