It’s been a while since I last posted a Killer Sudoku variation. As far as I can remember, you folks liked the Butterfly layout of the puzzles, so here is an overlapping, 4-in-1 (Gattai-4), Killer Butterfly Sudoku puzzles. You can also find these puzzles in my Killer Sudoku Compendium book. Killer Butterfly Sudoku for Friday, […]
