The way negativity was shown as far as BV is concerned it's all in relative terms.
To make one character look better in comparison they brought in someone who is even worse.They were all shown in comparison and through parallelisms.
Some decent men turned bad as in the case of Khazan Singh and Anop Shekhar they showed their characters as fairl decent men who loved their family and did their jobs with utmost sincerity. Khazan Singh was a kissan and Anop Shekhar was a jawan.They provided them reasons to feel hurt and insulted by their own family members.Dsa in the case of Khazan Singh and Alok in case of Anop.They felt slighted and decided to show them what they are made of - then took a wrong turn in life. Life taught them lessons in the light of that wisdom they got back on tracks.
Ratan Singh Akheraj Singh - They both are products of their own upbringing. Them and their reasonings are a sum of their own nature as well as the circumstances.Both were products of a very feudalistic society which advocates male supremacy and subjugating weaker sections of society as well as women .Their level awareness of the world around them is minimal.They barely venture out of their own comfort zone so they don't really know or understand how far the world moved aheafd and to top it all the education levels.These kind of people need exposure to the world outside they should be dragged out of their comfort zone. Ratan Singh was thrown into jail but also his desire to get back his child brought him in contact with people who live in a little more civilised world which changed his perceptions. Akheraj is also a frog in the well. But his desire to spread his horizons is going to bring him in contact with the world outside his comfort zone - it remains to be seen whether he is capable of embracing new world or not.
In front of Anandi Gauri looked so evil but in front of Sanchi she seems like an angel with all her flaws. Gauri and Sanchi ended up paying a big prize for merely wanting something that thye can't have. When that was denied to her Gauri found solace in her work Sanchi slipped into a dangerous zone by trying to drown her sorrows in the arms of another man.
Both had to receive real big knocks to realise that what thye have in life is much more valuble than what they can't have.Now both are at peace with themselves.
Dsa - this woman keeps evolving and never ever stops her attempts to undo the damage she had done in the past. She grabs every opportunity she gets to do something good.That is why this lady looks so different from what she had been and yet remains the same. Change is the only constant thing in her life.
Jagya - Needed a lot of knocks to reach where he is now. His transformation began the day when he realised he is being punished by life for his own deeds and since then no turning back for him.
Every negative charcter or a good character gone bad had a graph
Most of the times it is not the good who punished them but their own life has punished them and made them see light.