Logic Masters Deutschland e.V.

This puzzle was previously posted on PuzzleSquareJP using the another nickname Toki and a little fixed. Each step is not too hard, but I think this puzzle is overall tough because it requires some tricky steps unique to chaos construction. Please leave a comment if you need a help, Enjoy!

Rules

• Chaos Construction:
  Fill in each cell with a digit such that each row, column, and region contains every digit from 1 to 9 once. Each region is orthogonally connected and must be determined by solver.
• XY-Sums:
  A clue outside the grid indicates the sum of digits in the Xth to Yth cells in the corresponding row or column from the clue, where X is the digit in the 1st cell and Y is the digit in the 9th cell. Also, the Xth to Yth cells must belong to the same region and two region borders must be drawn on both sides of that region. Question marks indicate any integers.
• Inequality sign:
  An inequality sign points to the smaller digit.

Example of XY-Sums

The following grid shows valid XY-Sums clues.

Main puzzle

Play main puzzle on CTC App or Penpa+.