I Will Not Be The Supporting Character Forever

Why a supporting character instead of the main character?! And out of all supporting characters, why must I be this girl When she came to, she was in the middle of the novel, [Empress Rosalynne], as the supporting priest character, Elena. Moreover, the story starts right after Elena messed up a holy ritual and she was treated awfully by everyone around her Theres only one way to get out of this! I have to become the tutor of the Emperors little brother, Duke Levi! Elena thought she could watch over the protagonist of the story, Rosalynne, as the events of the story unfolded at the imperial court, but something was wrong. Equality between commoners and me, a noble? You better watch yourself! The protagonist she had admired so much was a villainess that discriminated against others based on their social status. I wont be able to stand it if everything ends up the way she wants! And so, Elena resolves to change how the story unfolds. Can she rise from her role as a supporting character and claim the position of protagonist?!