Missing number was scary.
In the old pokemon red and blue gameboy color games it was possible to find some freak of nature pokemon that was so inconsistent it changed levels after every battle. It made me creeped out just like pokemon tower... but it would have been even scarier if it had a status effect called"bloody" where your pokemon's sprite has a red pool of blood under it permanently and drains life bar as you walk forever. I miss feeling afraid in that way, it wasn't really fear, but it was almost.