Logic Masters Deutschland e.V.

This puzzle was created for zetamath's octoquadri setting challenge.

Solve online:

SudokuPad

Rules:

A grid contains eight of the digits 1–9, which appear exactly twice each. Digits may not repeat within a grid’s row, column, or 2x2 box. The omitted digit from each grid must differ (which the solver may keep track of at the top).

• Whisper (green): Adjacent digits on a whisper differ by 5 or more.
• Renban (purple): A renban contains a set of consecutive digits (not necessarily in order).
• Parity (red): Adjacent digits on a parity line alternate between odd/even parity.
• Region Sum (blue): Digits on a region sum line have the same sum in each 2x2 box the line is in.
• Entropy (orange): Every set of three sequential digits on an entropic line contains one digit from {1,2,3}, one from {4,5,6}, and one from {7,8,9}.
• Ten Line (light gray): A ten line consists of one or more contiguous groups of cells, each of which sums to 10. Groups cannot overlap.

(Note: The parts of lines in between grids are ignored. For example, R4C2 of Grid 3 and R1C2 of Grid 6 are considered adjacent and therefore will have opposite parity.)