Ghost Attack Trends
Before we go anywhere, let's get this one thing straight: Ghosts are evil. Why? Because we said so. Specifically, we have decided that ghosts aren't human, but they're (at least somewhat) intelligent, so they must be evil. Don't question us, we're totally experts on this completely unexplored and unexperimented field! We made our assumptions long before we ever saw any ghosts, and once ghosts did start popping up, we immediately began biasing our observations in accordance to our assumptions, so we are always right. That's definitely how science works.
So far, what we see is that we are very bad at identifying ghosts, which is probably due to the fact that most of them move very quickly and are difficult to pin down, especially when they're fighting.
Ghost X
Here is where I'd put an obligatory joke about how "X marks the spot" if I were really bad at unoriginal jokes and really good at making people very exasperated. We don't know very much about this ghost because we always shoot before we ask qustions, like we do with all ghosts. What do you mean this means we never get a chance to talk to and actually learn about the ghost. Why would we ever need to do that when we already know all we need to know about ghosts (that they're EVIL and probably here to make us miserable)?
All Unnamed Ghosts
Listen, we're super bad at naming ghosts. You should've gotten that impression from the fact that the first one is literally called Ghost X. This is kind of a placeholder for until we make up names for all the other recurring and non-recurring ghosts we see. Sometimes they yell what they call themselves but those aren't real names because they gave those names to themselves and clearly only humans (which ghosts are not, even though they can sometimes come from dead people, because once you die you're evil, obviously; have you never read about Moldyshorts and his Gravechewers?) can give actual valid names.