Unless I am mistaken and don’t remember correctly, I don’t remember Shivanya thinking Rithik as one of the killers. I don’t think she thought of him as that. She married him to get into the family. That was grey of her character to separate the girl who was in love with Rithik and stop their marriage the day they were suppose to get married and take her place in the marriage. She didn’t want to get close to him because she hated his family and thought may be he’s also like them meaning evil, but she didn’t hate him either or wanted to kill him. She didn’t think him to be a killer and later when she did fell in love with him, she couldn’t be with him as Naagin and human can’t be together according to N1 universe laws. So at first, she tried to stay away as she only came for revenge and just used Rithik to get into the family and later she tried staying away as she didn’t want to fall in love with a member in the same family and Shesha tried to make sure she doesn’t as both knew Naagin can’t be with a human. Shivanya was ruthless in her revenge and quite grey too at first when she took another girl’s place in the mandap. I mean that girl was in love with Rihtik since childhood and Rithik too agreed with the marriage until he saw Shivanya and fell in love with her at first sight love. Shivangi was emotional as I guess she lived a human life since childhood and then turned Naagin. And Bela is the most emotional of all even though she should’ve been the most ruthless and the most powerful as she’s Naagrani. She forgave Vivi so easily which was so surprising. I know forgiveness is good, but sometimes it’s not like she was even letting go Mahirs mom many times even. Most of the times Bela is too good for a Naagin. Shivanya would have never done that. She was the most ruthless and the least emotional among all Naagins. Sometimes grey too. But I loved her the most and could connect with her the most ❤️