Balance the Numbers
You made it? I didn't think you had it in you after it took you so long to solve Medium.
I'll let you try Diabolical, I am not liable for any destruction of ego that may occur. Enjoy the gray square!
Diabolical
Shapes:
If middle cell is ≥ 10: +1 to each cell. Otherwise: +2 to each cell.
If middle cell is odd: +1 to each cell. Otherwise: +2 to each cell.
Rules:
1. Each cell must be filled in with either red or blue.
2. When the puzzle is complete, the sum of red and blue numbers in every column must be equal.
3. Forming shapes of the same color changes the value of those numbers. Each cell can only be a part of one shape at a time.