I know this has been posted before, but I just wanted to ask what the spawn rates for the Withered Demon and the Forlorn were, as I am having a hard time finding both. I have encountered the demons before, but have yet to see an "evil" or "invading" Forlorn in the wild.

The wiki states their respective spawn conditions, but it seems that the rates are just so low that even in my ≈500 hr. playthrough I have seen the Withered Demons less than 10 times and the Forlorn never.

Thanks for your time!

You can change the spawn rates in the config file. Though I'm kinda surprised you say the forlorn were rare, they were absolutely everywhere for me.

If you have a lot of other mods with mobs spawning in the same areas, then they will likely take up most of the spawn rates that would normally go to the Forlorn. You can increase the spawn rates in the config like Nolan said.