Logic Masters Deutschland e.V.

This puzzle is inspired by Playmaker6174's Cavernous Japanese Sum: Deconstruction (9x9) and (11x11). Estimated difficulty is a harder 4-star.

• Chaos Construction: Place the digits 1-9 exactly once in each row, column and region. Regions must be deduced. Eight of the regions are orthogonally connected. The ninth region is centrosymmetric about r5c5 and each row and column contains exactly one cell from the ninth region.
• Japanese Sums: Each cell has two values: a digital value and a cave value. Digital value is the digit contained in that cell and cave value is the total amount of cells seen horizontally and vertically from that cell, including itself, where region borders and the grid perimeter block the visions.
  A circle clue outside a row/column corresponds to exactly one continuous group of cells that share the same region in that row/column, and its value shows the sum of all values(digital values and cave values) in that group, if given.
  The correct order of the clues is from left to right for the row and from top to bottom for the column. It's possible the same region can represent multiple groups in a row/column.
  '???' can represent any digit from 100-999.
  '??' can represent any digit from 10-99.
  '>??' can represent any digit from 11-999.
  An asterisk (*) shows an arbitrary number of circle clues, which can be none at all.
• Observer: There are nine Observer cells in the grid, exactly one in each row, column and region. The Observer cells have to contain a complete set of the digits 1-9. All Observer cells are centrosymmetric about r5c5. For a Observer cell containing digital N, its digital value is N+N and its cave value is N (exactly N cells seen from that cell).

CTC app link: Click Here (no answer check)

Example:
For example, 4 is in a Observer cell, the cell has digital value 8 and cave value 4.