Game Freak is getting more bold and degenerate with each generation.

Gen 6: Shauna (shamelessly horny for protag, first real example in a Pokemon game). Lesser versions like Lyra existed before, but they are all rated E for everyone while Shauna gives you TM Protect after the two of you watch fireworks alone (ok devs).
Gen 7: The loli generation (lmao). Lana, Mallow, Lillie, Hapu, Acerola, and for SOME reason the female protag in this gen looks way younger than usual (lol). Lillie is the Rated for E for Everyone version of Shauna with "more depth and less horny". Lusamine and Wicke add mommydom, foot fetish, hypnosis fetish.
Gen 8: Sonia, Nessa, Oleana, Marnie, Klara...etc. As you can see Game Freak has reached peak degeneracy, where they are no longer afraid of alienating the normalfags with designs that are totally kino, but arguably more fitting for a dating sim than Pokemon game. They sacrificed good games for god-tier waifus. This trend will only continue.
Gen 9: I expect someone in a gimp suit at this point (does oleana count)