Normal Sudoku rules apply (yay!). Digits along a purple or red “renban” line MUST ALL repeat, and MAY NOT be chosen from consecutive digits (i.e. 445577 is valid but 445566 is not). Digits along a grey palindrome line MUST NOT read the same in both directions. Digits along a thermometer MUST NOT increase from the bulb end. Digits along the negative diagonal (marked in blue) MUST ALL repeat. Diagonals indicated by arrows outside the grid MUST NOT sum to the indicated value. Clues outside the grid MUST NOT be valid X-Sum or Skyscraper clues, as defined below. In a valid X-Sum clue, the first X digits seen by the clue, where X is the first seen digit, sum to the number in the clue (i.e. 382xxxxxx would be a 13 clue). In a valid Skyscraper clue, consider the digits as heights of buildings, where taller buildings hide smaller buildings behind them. The clue outside the grid indicates how many buildings can be "seen" from the clue (i.e. 462187593 would be a 4 from the left (4 → 6 → 8 → 9) and a 2 from the right (3 → 9).