Every actor has contributed to a gripping tale with their best. As people have written let me clarify, its not based on HIndu Mythology - It uses Hindu Scriptures to build a plot.
Personally I don't like such endings, I understand there might be a second season hence the need to end it like that, but then the sacrifices of good beings is more than warranted. I believe even if it is actually happening in the society media needs to project a light of hope at the end. In the first season only the "Dark Side" as you may say has won, immaterial of what the second season brings.
Having said that a fantastic serial till end for me and perfect acting skills of everyone involved makes it a "SUPER GLUE".