I felt no pity for Cesar (spoilers)
The only reason he was in such pain for what he had done was because it turned out that Jean had been his own son. If Jean had been somebody else's son, he would not have had such a repentant reaction. His final letter to Manon, to the very end, was utterly selfish. They don't show her reaction, but I would hope that she threw the letter away and sold off that cursed land, just to show that she refused to treat it like it was her family inheritance.
Actually, I do pity him for one tragic thing: the fact that he didn't receive Florette's letter. That was beyond his control, and one could see that he really did love her. But considering how easily he killed a man over insults and land, let alone destroyed a stranger's hopes and dreams, it all shows just what a cruel man he was. He deserved such a punishment as he got.