Logic Masters Deutschland e.V.

Normal sudoku rules apply.

Normal anti-knight sudoku rules apply for the red, green, and purple digits only.

All digits in circles are odd.

The question marks outside of the grid are unknown skyscraper clues (how many buildings are visible from that vantage point in the clue’s row, column, or diagonal).

Any red, green, or purple digit that has a question mark in its row, in its column, or pointing at it via diagonal, must be visible by at least one skyscraper clue.

Every skyscraper clue that is unveiled must be placed in the last cell of the row, column, or diagonal that it sees. For example, whatever digit the skyscraper clue outside of box 3 is goes in r3c1.

*The clue outside of box seven is working double duty, but that does not mean the same digit must go into r8c9 and r1c7.*

SudokuPad link