Logic Masters Deutschland e.V.

Normal sudoku rules apply inside the 9x9 grid.
Split Peas: digits along a line must sum to a two-digit number, where the 'tens' digit is in one circle and the 'ones' digit is in the other.
Skyscraper: clues outside the grid give the number of digits visible in the adjacent row or column, looking in that direction, where higher digits block the view of lower digits.
Quadruple circles: digits inside the smaller white circle must appear in the four surrounding cells.

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This puzzle was made for Scojo's annual Secret Impostor event, in which I was charged with imitating SamuPiano. It was close, but ultimately voters were not convinced that mine was the real Samu puzzle, which, fair enough. The real SamuPiano never would've used that quad circle.