There should be a character in the Halloween event that’s a fatal error message. Fatal errors fit perfectly for Halloween because they’re so scary.
and special entry / departure messages
instead of your typical lines such as “a frozen knight has appeared!” or “the frozen knight left for someplace warmer”
it should be
entry: “A FATAL ERROR HAS OCCURRED IN MEMORY ADDRESS 0x00007B”
exit: “THE APPLICATION HAS STOPPED RESPONDING AND WILL NOW CLOSE”
Maybe have a jumpscare that pops up the fatal error window