She's the Antagonist

What is antagonist? 
"The antagonists may also represent a major threat or obstacle to the main character by their very existence, without necessarily deliberately targeting him or her and I say in every Antagonists there hide a great personality. Why? because the Protagonist would be useless and would not shine if there's no Antagonist."

But in this story, The Protagonist will be the Antagonist of someone's life.

"Yeah right! your the great Antagonist!" He shouted out loud