Logic Masters Deutschland e.V.

This puzzle was inspired by a childhood game called "7 Boom", you may know it as "Fizz Buzz". Players take turns to count incrementally from 1, replacing any number divisible by 7 and any number that contains the digit 7 with the word "Boom". For example: ... 12, 13, Boom, 15, 16, Boom.
Happy solving!

Rules:

Normal sudoku rules apply. Place the digits 1 to 9 in each Row, Column, and 3X3 box.

Yin and Yang: Shade some cells such that all shaded cells are orthogonally connected and all unshaded cells are orthogonally connected. No 2x2 area may be fully shaded or fully unshaded.
Orthogonally adjacent shaded cells cannot sum to a multiple of 7 or a number that contains the digit 7.
In addition, adjacent shaded cells cannot form a 2-digit number (reading from left-to-right or top-to-bottom) that is a multiple of 7 or contains the digit 7. For example, a shaded domino with 12 is valid, but 21 is not allowed (21 is a multiple of 7). Also, a shaded domino with 34 is not allowed in any order (sum to 7).

Killer: Digits in a cage cannot repeat. Digits in shaded cells inside a Cage sum to the clue in the top left corner of the cage.

Inequality: The inequality points to the smaller of the two adjacent digits (R9C8 is smaller than R9C9).

Solve online: CTC, CTC with valid shaded dominos, F-puzzles