Yami Ochi Ouji, Imayo wa Watashi ga Tenazukete Misemasu

I will stop your descent into madness! Izelia, the "late-blooming, impoverished young lady," is set to marry Radil—a royal feared as the "cold-blooded duke." But her married life with this dangerously alluring handsome man ends in a gruesome fate…? And then, an unexpected second life begins. Though Izeria struggles to avoid the worst fate, Radil's behavior seems different from before?! Original Webtoon