Arjun/Purvi/Pari---Anurag/Prerna/Prem (illegitimate baby)
Soham (Vishnu)/Archana-- Prem(UD)/Prerna (Archana is just like Prerna because of her mistakes she keeps on losing her son)
I have a feeling once Soham gets married to a nice girl. That girl will fight for his rights. Then Soham will change seeing the goodness in that girl.