Isekai'd as a side character

LJ, a woman who vowed to change the destiny of the villain. Azef, even if she has to trample everything on her path. Will she be able to save him while keeping her magic crest a secret at the same time?
○
○ : domestic abuse; alcoholism; torture; strangulation

I’ve been transmigrated as Leticia, a side character from an otoge. I was then forced by my twin sister (who by the way, has the worst personality) into taking Lionel as my fiancé. The first time I met Lionel, he was nothing but chubby and fat, just as the rumours said. However, me being me, I realised that Lionel was an unpolished gem with potential to shine, so I decided to re-invent him.
○

My husband, whom I married in an arranged marriage, is the 'second male lead' who has a one-sided love for the female lead of the novel I've been reincarnated into, [The Saint's Wish]. I, the original wife, am a character who dies a mysterious death amidst a lonely married life. So to survive and for his happiness, I tried to get a clean divorce, but...
○