Logic Masters Deutschland e.V.

This puzzle was set for Scojo's impostor series. I had the honour of impersonating ThePedallingPianist. This puzzle is a combination of things I think of when I think of ThePedallingPianist. The biggest one is that before you can start placing digits, you must discover some truths about the grid.

You can see the original version here, which contains a long rambling story about the setting prompt and the puzzle (another TPP hallmark) and includes explanations for why the chosen constraints were used.

The revised version, with condensed rules text, can be found here. Outside of the rambling text box, the two versions are identical.



Rules:
Every row, column and 3x3 box contains the same set of ten digits, chosen from 1-9, but this set might repeat some digits and omit others. No digit appears more than twice in the set.

Unique sum S-cells: Each row, column and 3x3 box contains an S-cell, which contains two digits. The value of an S-cell is the sum of its digits, and no two of the S-cells have the same value.

Renban: Values on a purple line form a non-repeating consecutive set.

Thermometer: Values on a thermometer increase from the bulb end.

Zipper: Values an equal distance from the center of a lavender line must sum to the value in the middle of that line.

Ambiguous diagonal: Values cannot repeat along one of the main puzzle diagonals (positive or negative). It is up to the solver to determine which diagonal this applies to.

3 in the corner: There are no 3s in the corner of this puzzle.

Kropki: Values separated by a white dot are consecutive; values separated by a black dot are in a 1:2 ratio.

Fortress cell: A fortress cell, denoted by a red square, has value greater than all of its orthogonal neighbours. All fortress cells in box 6 are given.

Inequality: An inequality sign points at the lower of two values.

I'm not sure whether to rate this 4* or 5*, it's probably somewhere inbetween.