Life is full of contrasts, and so is this puzzle. The pink lines pull things together, while the global entropy rule pushes things apart. Push, pull, pushmi-pullyu, back and forth and then things fall apart.
Or fall into place, and the puzzle is solved!
Rules:
Normal Sudoku rules apply.
Renban: Digits on each hollow pink line form a non-repeating set of consecutive digits in any order.
Global Entropy: Every 2x2 area contains at least one low digit (123), one medium digit (456), and one high digit (789).
Estimated difficulty: 2.5 out of 5
Solve on SudokuPad