Antagonist
Antagonist contains the prefix ant- which means against. The antagonist is the person, idea, force, or set of circumstances that opposes the central character. For example, Voldemort in Harry Potter is the antagonist. The ocean is the antagonist for Marlin, Nemo's dad, since he has to cross the entire ocean to find his son.
A motif is a dominant idea in a literary work. The protagonist is the good guy or main character. The central conflict is the main problem faced by the protagonist.
