I love SillyTavern. I've been doing a Pokemon adventure where I'm playing Red during the tail end of the two years between gen 1 and gen 2 (before he battles Gold/Ethan on Mt. Silver). I have a huge Pokemon world info/lorebook loaded up so I run into all kinds of characters. Whenever I meet someone important (gym leaders, fellow MCs), I spin up a quick character card for them and bring them into the group chat. I came across Hilda and battled her, for example, and a little while later Brock just happened to cross our paths.
It's not perfect, but it's pretty fun when you're not having to hold its hand, and there's real potential for a true role-playing game experience here once the technology develops. Can't wait.