An Otome game novel where MC trains to change the fate of any character or him/herself. Fine with any gender. Sort of like Akuyaku Reijou ni koi wo shite.
https://www.novelupdates.com/series/the-world-of-otome-games-is-tough-for-mobs/ Akuyaku Reijou wa Ringoku no Outaishi ni Dekiai Sareru
Tensei Kizoku wa Taishi wo Idaku!. It is one of the rare novel of that kind where the mc wants to have power , money and womens. He is scheming and often use his Wits. It s slow and let things build. Mc wants to overthrow the kingdom and become a king. He starts scheming against his brother to become the heir from his childhood and start to scheme for 10 years later. Sometimes it s a bit slice and life but the overall plot is advancing .
It's a Gal Game, but there's Magical Explorer. The Gun Weilding Villainess get's stronger to protect herself and can protect others Does I'm Not a Villainess! and Love for Sake count? They were kind of OP from the get go but are learning as they go to protect those close to them. Level 99 Hidden Boss has her getting strong. Not motivated to protect anything though. Just a gamer who got isekai'd into a game world. Plus, no training phase. It's literally just the prolog.
Falling In Love With the Villainess https://www.novelupdates.com/series/akuyaku-reijo-ni-koi-wo-shite/
Already read Akuyaku Reijou, also Otome game survival, wonder why v2 isnt getting tl'ed though. Wanted to reread Magiero but it got licensed. I'll try Gun wielding villainess and Im not a villainess. Read Love for Sake And Hidden boss already