nah. it’s more likely to be oscar given how he has put off his marriage until he’s 28 when in the first life he married ines at 20, how he abused/picked on carcel for "stealing" ines since they were kids (because ines had the best bloodline in the whole empire to be crown princess but she picked carcel in this life instead). it goes to show that the crown prince is obsessed with ines and probably wanted carcel out of the picture so he can marry ines.
also, emiliano couldn’t have had the resources to even attempt an assassination on such a high profile person as carcel because he’s not just the most handsome sought-after man in the empire, he’s also a well-respected naval officer, as well as cousin of the crown prince. emiliano is just a commoner after all.
Why i feel the person who's trying to kill carcel is emiliano. I feel he had his memories from the start. Just like inez, and his trying to get his lady