Anti-Knight Anti-King Little Killer Sudoku Rule
Anti-Knight Sudoku + Anti-King Sudoku + Little Killer Sudoku
Anti-king sudoku rules: no two squares that touch either horizontally, vertically or diagonally can have the same digit. (As in, no two squares a chess king can move between in a single move.)
Rules of Anti Knight Sudoku Puzzle
Place a digit from 1 to 9 into each of the empty cells so that each digit appears exactly once in each row, column and 3x3 outlined box. Additionally, no two identical digits can be a chess knight‘s move away from each other (as shown in the diagram).
Anti-Knight Sudoku + Anti-King Sudoku + Little Killer Sudoku