Logic Masters Deutschland e.V.

Normal sudoku rules apply. Place the digits 1-9 once each in every row, column, and 3x3 box.
Imposter: Shade exactly one cell in every row, column, and 3x3 box. The value of an unshaded cell is its digit. The value of a shaded cell must be deduced by the solver. The shaded cells form a complete set of the digits 1-9 and a complete set of the values 1-9.
Killer: Values in a cage sum to the total given in the top-left corner of that cage. Values can repeat within a cage, though digits cannot.
Kropki (+): Values separated by a white dot are consecutive with one another. Values separated by a black dot are in a 1:2 ratio with one another. Not all dots are necessarily given.

Play on SudokuPad (uncolored)

If you aren't familiar with the Phistomefel Ring, consider watching this video from Numberphile before attempting this puzzle.