It’s a big one, and it’s anchored by Gravity Cages at the bottom. While these cages don’t directly affect anything else in the puzzle, I like to imagine they’ll combine to form a black hole, pulling everything in all four grids into a single cell.
Rules:
Normal Gattai-4 rules apply. That is, there are four overlapping 9x9 Sudoku grids. Within each Sudoku grid, each row, column, and 3x3 box contains the digits 1-9. Overlapping boxes are shared between the overlapping grids.
Digits within cages sum to the small number in the top left corner of that cage.
The marked diagonal contains the digits 1 to 9 exactly once.
Renban: Digits on each pink line form a set of non-repeating consecutive digits in any order.
Gravity Cages: Within cages marked with an arrow, digits do not repeat, and larger digits are pulled in the direction of the arrow. That is, no digit is higher than the caged digits below or to the right of it.
Digits on thermometers strictly increase from bulb to tip.
Estimated difficulty: 3 out of 5
Solve on SudokuPad