Few spoilers

It's quite long so I've only red few spoilers—and also I didn't finished the manhwa yet lol
1. who's actually killed mc?
—The duke from the mc's country—so basically not his brother
2. why mc's brother became a tyrant?
—He has illness and refused to be treated and he's obsessed with the mc to da point he graped whoever the mc resembles and killed them after, only Evans spared(he is his knight who resembles the mc the most)
3. DID THE PAST MC FUCK HIS PRESENT SELF AT THE PAST???
—I don't know abt this but I have red that the mc's father—the emperor preserved his body bcz he couldn't accept his mighty son's death(?) dunno if I interpret it right, and about the mc's killer, the emperor doesn't want to revealed that his mighty son was killed by a merely duke, only few people know abt it—that's why the people think it was the mc's brother who's behind the assassination
4. AND OMFG CHRIS???
—The ml came to knew that Chris liked the mc but doesn't deal with it bcuz Chris saved the mc I guess a few times and the ml knows Chris is loyal to him

5. Ending
—Ray became emperor in his own country and asked the ML if he wants to become his concubine—I think the ML agreed only after he dealt with his responsibilities first in his country. Sadly, it didn't show it happened—so it's bittersweet for some. But it's a happy ending