The Villainess Once Said [Official]

"On this day, six years from now you will die. Della Limiere, because you are the villainess of this novel."
Envious of the opportunities she never had as a girl and eager to learn about new things, Della hears a shocking prophecy from Lissha.
She must change her fate and marry a supporting character in order to survive.
But why is the emperor threatening this guy and why was he almost assassinated…? Is he really just a supporting character?
Then fate takes a turn, and the truth becomes a lie…
Will Della survive to the end?