itch.io

even crowdsourcing or having a suggestion box could probably get you the basic mechanics and some world or universe building in for at least the first 4 cultivation realms. qi - foundation - core - nascent

btw as long as you contact some authors of web novels, they would probably be happy to write some lore or at least give a foundation for lore

PS: registered just to say this.

This has the best potential of any game I've seen on here, and there is an embedded audience as it's essentially an interactable web novel, would be interested in investing in it if you are committed to making this a full game, or consistent updates at least.