The main conflict in the story is between the hero and the villain.

The opposition of persons or forces that gives rise to the dramatic action in a drama or fiction.
The conflict was intense.
Avoid unnecessary conflict.
Their conflict ended peacefully.
internal conflict
armed conflict
avoid conflict
disagreement
clash
struggle
The siblings had a conflict over who would inherit their parents' old house.

A serious disagreement or argument, typically involving differing opinions or interests within a familial context.
The friends had a conflict about the game.
A small conflict arose over the last cookie.
Their conflict was about a silly misunderstanding.
avoid conflict
resolve conflict
internal conflict
disagreement
dispute
argument
The conflict between the two neighbors lasted for years.

A serious disagreement or argument, typically a protracted one.
The conflict caused much pain.
Avoid unnecessary conflict.
Their conflict was loud.
avoid conflict
resolve conflict
internal conflict
disagreement
dispute
quarrel