The Heiress's Bargain

So this girl Evelyn gets screwed over by her stepsister and ends up in crazy debt. She's forced into a fake marriage with a rich guy, Sevion. She moves in and finds out her mom's old pendant is actually the crest of the Whitmore family—and that she's the only heir. Turns out her grandfather was killed and his fortune stolen by rivals and corrupt elders, and Sevion's family was in on it. He only married her to use her against those elders. But eventually they become real partners, take down the elders together, and win everything back. Fake marriage turns into real love.