The Villainess’ Butler: Death Flag Destroyer at Your Service (2020)

Blurb:
“To stay by your side, I’d defy the gods themselves.”
A reincarnation story with a twist! I, Cyril, have been reborn in a new world and pledged myself to save Lady Sophia, the villainess of an otome game, from the many horrible fates that await her! I’ve raised her to be a proper young lady, keeping her from turning to the dark side … but apparently, she’s developed feelings for me. And now the game’s heroine has appeared, putting all I’ve accomplished at risk. Still, as her all-knowing butler, I will defy fate and ensure milady’s happiness!

Source: www.anisearch.com/manga/57691