It's been a while since the evil spirits were killed, and now they're still there. The jade tablet is still protecting the owner of it, and it's still alive. The evil spirits are still there, and they can't be killed yet. The only thing that's changed is that the green qi on the tablet is now a symbol of the soul of the evil spirit, which means that evil spirits will always be around, even after they've been killed. This means that the next time evil spirits re-enter the world, there's a good chance that they'll be dead.