differences between Xianixa and HGG
Design philosophy: Xianxia is an all-in chinese light novel inspired ascension game. Big big big big numbers, big abilities, tons of nameless mooks that die from your thousand soulforce dual wielding divine wrath axe charge. None of the base game's lore is preserved, and many characters are giant 10 foot tall super strong combatants or anime maids.
HGG is restrained to CoC lore and power levels closer to the base game, though with expanded content. Xianxia also has very poor English, while HGG rigorously corrects the English in all submissions.
Mechanics: Xianxia has a million perks and abilities. HGG is more like the base game with a few dozen abilities and maybe an extra 20 perks. The writing is more the focus. There are no nameless golems with 0 sex scenes just padding out combat, but you also aren't getting universe-tearing samurai sword that you attack 30 times a turn with. Expect HGG to be like vanilla+.
Writing: HGG is in English, and tries to stay in line with the lore of the base game, correcting inconsistencies in the writing, and developing characters that are already in the game in ways that stay in line with their personality and backstory. A lot of sex scenes are added, and there is a lot of expanded support for strange body types like centaur and naga (though still not as good as being a biped)
HGG takes removes some cuckold content
They only removed cuckold content that was unique to them in the first place. You can soft-disable some of the vanilla game's with some changes to choices, like it's easier to keep helia from being slutty with the fox girls in the bar and you can disable Urta so there's no Urta x Amily scene. But no cuckold content was removed that was in the base game. HGG never removes anything from the base game unless it's actively inconsistent, like changing Akbal's sprite from a black panther to a jaguar, to match his writing, and fix some later addition scenes that called him black. He was called tan-furred in early content.