Everytime I get into those power fantasy novels/mangas, I always hoped it would be bl, or have a high amount of bromance in it lol. Similar to 'Regressor Instruction Manual' where the bromance could be mistaken as romance XD. I also enjoy the 'super loyal willing to die and hates everyone but Mc' friend/servant. Similar to Asmodeus from Mairimashita Iruma Kun. Very fun to watch honestly. It scratches a certain itch in my soul.
The Legendary Master’s Wife Sick Beauty [Rebirth] For manga you could try Koori no Mamono no Monogatari Silver Diamond (same author as previous)
You're welcome. I hope you'll like them. I personally really liked The Legendary Master's Wife and the Koori manga. They are both among my favourites and I read them several times.
Second the recommendation of Legendary Master's Wife. Also one of my favorites and reread many times! You may also like: https://www.novelupdates.com/series/the-founder-of-diabolism/ https://www.novelupdates.com/series/peerless-immortal-surrounded-by-demonic-disciples/ https://www.novelupdates.com/series/this-venerable-one-really-didnt-abandon-my-familiar/ https://www.novelupdates.com/series/rebirth-of-the-supreme-celestial-being/ https://www.novelupdates.com/series...cubs-i-became-the-wealthiest-in-interstellar/ https://www.novelupdates.com/series/its-not-easy-being-a-master/ https://www.novelupdates.com/series...ng-my-disciple-from-turning-to-the-dark-side/
Heaven Official’s Blessing is a good one. BL, with a powerful MC and an ML who dislikes everybody except the MC.
Not sure if they are quite what you're looking for but maybe "Turning" "Transmigrated into a Female-Oriented Card Game" "Supernatural Movie Actor App" "Regression Guidelines For the Supporting Character"