Delirium and Her Pings
Have you ever wondered what makes Delirium ping? No? Well then why did you click the cut? Really, though. Delirium, from Neil Gaiman's The Sandman, is a very complicated yet simultaneously simple character. Being the anthropomorphic personification of insanity, she possesses a very well veiled method to her madness, a deeply hidden sense of order. Her interests are constantly in a flux, but some things never (or rarely) change.
Welcome to the comprehensive guide to what attracts Delirium's attention. We will focus on living beings, people and entities, since that comprises the majority of CFUD inhabitants. Sorry, no one cares about the pet rocks and sentient spoons but Delirium. :| Alas.
The Drunk
Drunk people are those under the influence of alcohol to an excess extent. Plain and simple. It should come as no surprise that drunks and their antics would ping Delirium. She likes drunks. From their perspective they're nice, even the mean ones. She always agrees with them completely.
Ping Value: 7 out of 10.
The Insane
The insane are those who belong to Delirium. No question about it. They are hers, and she fully recognizes them on sight. They became hers by leaving behind too much when they brushed against her realm. Only those who are already deeply insane can travel through her realm unscathed - or nearly unscathed. After all, insanity is on a scale. People can easily become more insane.
To be considered insane you must be missing a piece of mind. Or peace of mind. This could be a lack of unity, such as dissociative identity disorder, or a defective function of mental processes like reasoning, such as schizophrenia. Generally, any mental disorder that affects you in the above manner counts here. Some personality disorders may count, but only to a smaller degree unless in conjunction with a more severe disorder. There's more to it than this, but I'm sure you get the idea by now, if you hadn't already.
Delirium likes those who belong to her. She likes them a lot. These are the ones she most leaves her realm to visit from time to time. There are no particular types of insane people she prefers overall. It varies based on her whims. One moment she's all about the psychotics who hallucinate a lot, the next moment she's into the people with more than one person in their head. She's all about change and flux.
Ping Value: Case by case basis. Catatonics might only score a 1, whereas the really delusional might score 9 or 10.
Autistics/Asperger's Syndrome Afflicted
Autistics and those with Asperger's Syndrome, which are more classified as developmental disorders, are not a very big ping for Delirium. They just think differently. However, it is not uncommon for them to also be afflicted with a mental disorder of some sort, or personality disorder, or any other thing that would ping her. So the people in this category that do ping her would ping her for those other things.
Since they by themselves are not part of her realm she generally doesn't think about them. Think of it as Delirium's attention being occupied too much by others with higher ping values.
Ping Value: 1, if any. Higher ping values from other sections may override this.
The Otherwise Mentally Afflicted
This category is for everyone who is not insane, autistic, or afflicted with Asperger's Syndrome, but is still somehow mentally afflicted. Pretty much, you qualify if you have a mental disorder. Delirium is more familiar with only certain types of afflicted people. For instance, those with cognitive disorders: delirium, dementia, amnesia. Psychotic and dissociative disorders also rank highly. You may notice a pattern here: the more potential for the disorder to make someone hers, the more likely she will notice them. These are the types who will most easily wind up in the Insane category.
On the other hand, people with gender identity disorder, insomnia, kleptomania, or major depression aren't so high on the scale. These are more compulsions, inabilities and inconsistencies, as opposed to delusions. Majorly depressed people are more her sister Despair's area. Narcissists are more her sister-brother Desire's area. And so on. Eating disorders are faint pings, and really depend on the severity of the person's skewed trains of thought.
Ping Value: Case by case basis. Keltpomaniacs might only score a 1. People with OCD would score a 3 to 6 depending on the severity (Monk scores a 7 there).
Emperor Norton I would have scored a 9 but not really. Delirium herself states in canon that he's not really hers, and that his madness keeps him sane.
Those Under the Influence of Mind-Altering Substances
Remember the section about drunks? This one, about those who use mind-altering substances, is kinda similar but on a far greater scale. The types of drug use that would ping Delirium the most are hallucinogens, i.e. psychedelics, dissociatives and deliriants. This is because the effects of these drugs can mimic the types of psychological conditions that afflict people who belong to her, such as psychosis, schizophrenia and thought disorder. In her opinion, people who use these are coming to visit her. How nice of them. She likes to visit people, but it's always nice when they come to visit her.
Ping Value: Someone who's a little buzzed would rank a 2. Someone who's totally wasted would rank a 9 or 10.
Those With Skewed Perspectives, AKA the Special Cases
Some individuals have skewed perspectives. A good way to put it is, sane but operating on 'special' logic. This logic may or may not appear in conjunction with lacking morals. That depends on the individual's environment. Normally these individuals, be they people or not-people, would not ping Delirium much. However, these skewed perspectives may raise their Ping Value by a notch or two. It depends on the severity and vividness.
Ping Value: Case by case basis. Add 1-3 to their normal ping value.
People
To Delirium, a person is someone who is, or was, human/humanoid at some point and has not changed so much that they have become unrecognisable due to their current nature. Delirium is not a person. No one in her family is. People are the ones that her family generally interact with and watch from afar. They are the ones who are affected by her family's realms. A few examples of those who still classify as people despite the change they've gone through are Poison Ivy (a leafsy person), any vampires who were once human and have not lost too much of their humanity, and any shinigami who were once human and still retain a good deal of their humanity (like the ones in Yami no Matsuei).
Delirium will probably only notice or think about people who belong to her, or have the potential to. Exceptions may be made for those who could be or are severely affected by the realms of Desire and Despair. Maybe Dream too, in a small number of cases. Thing is, it's hard to get Dream to play.
Ping Value: See above categories.
Alternate Personifications of Delirium's Family Members
Delirium and her family members are all anthropomorphic personifications of universal concepts. In order of age we have Destiny, Death, Dream, Destruction, Desire, Despair, and Delirium. To Delirium, her siblings are the true personifications in question. This means that for example, should she come across a personification of Death from another fandom, she will likely react one of two ways: mistake that being for her sister Death, or obstinately insist that "You're not my sister."
Death seems to be the sibling most likely to have alternate versions of herself. Other fandoms might have their own versions of the others, but if they do, I currently am not aware of them.
Delirium would be able to sense their 'concept nature', but something would feel off about them.
Ping Value: 7 out of 10.
Shinigami
Shinigami. or gods of death, soul reapers, etc., get their own category. Delirium's favorite sister is Death. To Delirium, shinigami are people/beings who work for her sister. Death does a job that no one likes to do, but someone's got to do it. Therefore, it makes sense that she has lots of helpers. It's kind of like Santa Claus and his elves. It makes Delirium happy when her sister has an easy workload. Thus, Delirium likes shinigami. She likes them so much she licks them.
Ping Value: 5-7 out of 10.
Shapeshifters
Shapeshifting is a change in the physical form or shape of a person or animal. In most cases shapeshifters are people who change their appearance, or switch from male to female, or go from human/humanoid to animal. The Weapons in Soul Eater also count here. Delirium likes things that aren't what they are. So, it makes sense that she would like shapeshifters. In her own way, Delirium classifies as a shapeshifter.
Delirium may not necessarily recognise a shapeshifter as exactly that. However, she'd feel something. She wouldn't know offhand what it was. But it'd be there to niggle at her.
Ping Value: 2-4 out of 10. Inuyasha is a 5.
Homunculi
The concept of the homunculus is quite varied. Just try looking at its Wikipedia entry. One of the more generally accepted views is that homunculi are some sort of artificial human. They don't count as people due to lacking important human elements. For example, the homunculi in Fullmetal Alchemist are either created from scratch and deemed as super monsters, or were humans who transformed after having a Philosopher's Stone injected into their bodies. While the latter type is closer to humanity, neither type really sees humans as anything more important than ants. This feeling of superiority over humans, plus their ability to regenerate or revive from almost nothing, helps distinguish them from humans. Though not all homunculi outside of FMA are like this, some may contain similar elements.
Delirium doesn't think too much about homunculi. She can't even pronounce the word; it ends up as homo- homo... homo uncle. They are far less likely to be affected by her and her siblings' realms. She knows what they are, though. Ones with more concept of self, like the FMA homunculi, might ping her a little.
Ping Value: 1-2 out of 10. May be higher in rare cases.
Animals
Delirium likes animals. Her favorites are dogs and fish. She also really likes rats, since she likes to visit her sister Despair, whose realm is crawling with them. I'm sure she likes other kinds of animals as well, but the above are the ones that interest her the most. She's obsessed with doggies, created wafflepuppies, and has a talking guardian dog named Barnabas that her favoritest brother Destruction gave her on indefinite loan. Most of the time, she will mistake other doggies for her own. As for fish, she is rarely seen without any and often turns into fish. At one point in canon she takes the form of a shark.
Ping Value: Dogs are a 5-7. Wafflepuppies are 8. Fish are 5-9. Rats are 3-4. Other animals are 0-3.
Nobodies
Nobodies are fandom-specific to the Kingdom Hearts series. They are creatures without hearts. They are leftovers "born" in the in-between realm, and exist as the body and soul of people who lost their hearts to darkness. To Delirium, a Nobody is a thing untouched by her sister-brother Desire. They aren't much of a ping. However, this could change depending on the circumstances.
Ping Value: 0-2 out of 10.
Other Not-People
To Delirium, anyone who is not a person is a not-person. This includes Nobodies, homunculi, animals, some shinigami, and alternate personifications of Death, all of which have been covered already. In addition to these, other examples of not-people include things, places, demons, angels, gods and goddesses, celestial beings, and personifications of other concepts. I include places in this list due to the Sandman character Fiddler's Green. He is a place who is also a person. He would interest her because he's something he isn't. And he's nice. Gods and goddesses are from her brother Dream's Realm. Angels came from the Silver City. It's unknown where demons came from. Delirium's family are obviously not the only anthropomorphic personifications of universal concepts around. It makes sense that she can sense other beings like her. Overall, the beings and things in this category really vary as to Delirium's interests. See the various mindset categories if relevant. People aren't the only ones who can be affected by Teh Crazy.
Ping Value: Case by case basis. 0-2 in general. Gods and goddesses are a 4. Fiddler's Green is a 5. Personifications of other concepts are a 4.
That ought to cover everything. Please keep in mind that Ping Values are not absolute and are subject to change for special cases.