Logic Masters Deutschland e.V.

Rules:

• Normal Sudoku rules apply.
• Modular lines : every set of three sequential digits along a line must contain a complete set of residues modulo 3, i.e. one digit from {1,4,7}, one from {2,5,8}, and one from {3,6,9}. Digits may repeat on a line, if allowed by other rules.
• Modular squares : every 2x2 square must contain at least one of each set of residues modulo 3.
• Digits joined by a black dot are in the 1:2 ratio. Digits joined by a V sum to 5. Digits joined by an X sum to 10. Not all dots and XVs are given.

Play online using Sudoku Pad or F-Puzzles

In case you get stuck, here's a video solve