There are four yugas widely accepted in Hinduism. They are :
1. Satya yug
2. Treta yug (Ramayana)
3. Dwapara yug (Mahabharata)
4. Kal yug (Present)
In satya yug, the fight was between two worlds.( Devalok and Asura lok) Asura lok being the evil, was a different WORLD.
In Treta yug, the fight was between Rama and Ravana. Both rulers from two different COUNTRIES.
In dwapara yug, the fight was between Pandavas and Kauravas. Both good and evil from the SAME FAMILY.
Kindly note how the evil is getting closer
For example, from a DIFFERENT WORLD to a DIFFERENT COUNTRY to the SAME FAMILY.
Now, know where is the evil in Kalyug? It is inside us.
Both GOOD AND EVIL LIVES WITHIN. The battle is within us. Who will we give victory to. Our inner goodness or the evil within?