Reborn, She Let Her Sister Marry The Bastard

Betrayed and killed by fiancé Damian and stepsister Vivian, Scarlett is reborn with past memories, dumps the scumbag and enters a contract marriage with cold heir Ethan for revenge. They find Damian is their shared enemy, team up with also-reborn Vivian, collect his crime evidence, bring him to justice after life-or-death tests and turn their fake marriage into real love.