Logic Masters Deutschland e.V.

Draw nine non-overlapping 3x3 boxes, and place the digits 1-9 once each in every box. Digits cannot repeat in a row or column, and cells outside the boxes should remain empty. Throughout the grid, numbers with the same number of letters (eg 4 and 9) represent the same chess pieces (bishops, knights or rooks). Within a box, pieces cannot be in a position to capture their own type, (eg if 4 and 9 are in the bishop group, they cannot occupy diagonally opposite corners in a box). Cells on Xs sum to 10 and on Vs sum to 5, all are given.

playable link to the puzzle