Dave
Working as an Azkaban guard was a hard but ultimately fulfilling job.
Most of the lethifolds Dave knew looked down on its occupation, saying things like: "This is the easiest job ever! Ministry fleshies literally bring you fresh fleshies you can dry! It's so boring!", which Dave thought was a little unfair.
Sure, the job had some perks, such as good working hours and decent meals, but it also came with various responsibilities and sacrifices.
For example, barring extraordinary circumstances, dementor workers were not allowed to eat entire souls of delivered fleshies at once, instead they were expected to ration their meals, eating one happy memory at a time.
It was quite a commitment, and Dave doubted that any of its lethifold friends would be able to do such a thing, too used to their "independence," "freedom" and "flexible working hours." Sure, freelancing sounded nice on the surface, with the ability to choose food and eat to your heart's content, but it just didn't offer the same stability as a guard job did, especially in this economy.
(The job market for soul-suckers became pretty dry after the snake lich was banished from England. Most potential targets were more likely to cast a patronus on them than before. Quite a bummer.)
It was true, however, that the work could be quite repetitive. Approach a fleshie, eat their happy memory and move on to the next one, rinse and repeat. It didn't help that most of the fleshies were mostly the same, dark wizards and onanists, often already depressed and devoid of happiness even before reaching Azkaban. Well, sometimes their department got unique fleshies, different from the usual ones, but more often than not they caused more trouble than they were worth.
Like the Sirius Black fleshie, which recently caused quite a stir among the dementors.
No one knew exactly what happened, but during the summer one of their fleshies, Sirius Black, managed to escape from his cell with some outside help. Suffice it to say, it was quite embarrassing for the entire office. After all, their department had always prided itself on its perfect containment record, so the fact that a fleshie was not only able to escape from their prison, but also did so without anyone noticing, was simply humiliating.
Dave wasn't there when the Ministry fleshies found out, but apparently they were also quite upset, which was honestly quite understandable. After all, they worked every day to deliver new fleshies to the dementors, trusting them to do their job, and yet Dave's department was unable to keep them contained and drained, the one thing that was expected of them.
Supposedly they were even considering downsizing in the dementor department because of this mistake, or at least that's what Mindy from accounting told it. Then again, Dave always took its words with a pinch of salt, as Mindy was the biggest gossip in the entire office.
Anyway, because of the whole Black fiasco, the Ministry fleshies decided to assign some dementors, including Dave, to a special project. They were tasked with capturing/draining Sirius and bringing his empty husk back to Azkaban. Most of Dave's co-workers thought it would be quite a demanding job, with Ministry fleshies making their lives miserable for some easy PR points, but it turned out that their assignment was actually quite enjoyable.
After all, as part of the ongoing investigation, they were allowed to board a train full of young fleshies and devour their happiness! How great was that?!
This was quite a change for the ministry's fleshie department, as they were usually quite picky when it came to choosing food for the dementors. Dave suspected that they were trying to improve the morale of the dementors, who were already quite depressed by Black's escape, by providing them with a high-quality meal. Most of its co-workers probably hadn't had a chance to eat the young fleshie's soul before, so it was a pretty smart move in its opinion. For this reason, everyone on Dave's team was quite motivated to complete their task and ready to do their best.
They all even agreed to limit themselves to two happy memories per child so as not to slow down the investigation.
Dave itself was quite motivated too, as it had been 79 years since its last promotion. Maybe if it proved itself during the investigation, its actions would be noticed by its superiors, hopefully allowing it to move to the young fleshies' wing in Azkaban. Dave had heard rumors that the meals there are simply divine, so it couldn't wait to find out.
That's why Dave couldn't help but smile after boarding the train and approaching the door of the first compartment it was supposed to check out. This was its time to shine!
After composing itself and making sure it looked presentable as the ministry's representative, Dave discreetly pumped its fist for good luck and slowly opened the compartment door, full of determination.
Inside, Dave found three young fleshies shivering from the cold and looking at Dave's incorporeal figure with barely restrained horror. It was quite pleased with their reaction, as it was an appropriate response when seeing a government official on duty. It was nice to be respected.
When Dave finished relishing the sensation, it began to slowly look around the compartment to see who it was dealing with. Unfortunately Black wasn't in the compartment, not that it really expected a man to be there, but the young fleshies themselves looked promising as food. It could practically feel the delightful fear and pain they emitted, just waiting for Dave to devour their happiness.
The first fleshie, a male one, was quite typical as far as young fleshies go. The boy was looking at Dave in horror, clutching his wand tightly in horror and seemingly trying to think of some happy memory, judging by the mix of emotions and thoughts Dave received while looking at him. It didn't look like the boy would be able to cast a Patronus, so Dave wasn't too worried about his attempts. In fact, his desperation would make its meal even tastier.
The other, this time a female, was quite interesting. It was clear that she was afraid of Dave, looking at him with wide eyes and quivering lips, but the fear itself was surprisingly dull, as if it was suppressed by something. It didn't look like the kind of mind magic that adult fleshies used, so Dave just assumed she was broken in some way. Plenty of people like that were in Azkaban.
The third one was...
"JESUS FUCKING CHRIST! WHAT THE FUCK ARE YOU?!" Dave shouted in confused horror as its 'eyes' landed on the third fleshie, which was watching the dementor with detached interest, seemingly unaware of what a fucking abomination he was!
During its long career as a prison guard, Dave had seen countless fleshies of all kinds, some deformed in body, some deformed in soul, but nothing even remotely compared to what it was seeing at the moment. The more Dave looked, the more it was horrified by the sight, unsuccessfully attempting to make sense of what it was seeing. IT saw shapes, numbers and words, but with no connection, no sense, no logic!
But then something in Dave's mind hummed and it saw!
Jaded soul in hollow chest, logic twisting, bending, breaking!
Metal wire strangling head, there are distant stars on the tape!
Cuckoo nesting in the mouth, sends its children far and wide!
Stench of death, fakes the living, pretends breathing, feigning feelings!
Tangled mind, potent soul, hail the triumph of the void!
Overwhelmed and terrified by the unseen revelation, Dave staggered backward, instinctively inhaling the emotional ambiance in the air. Too late it realized that it contained a dark miasma leaking from the awful thing before him. It hastily dashed for the exit, already knowing that it wouldn't lead to anything good.
It was right.
Dave barely had time to leave the compartment and shakily close the door behind it when the inferno of pain erupted in its incorporeal body, flooding its entire being with unimaginable pain.
Everything went black.
As Dave regained consciousness (which was a fairly new sensation, since it didn't even know it could lose it), it found itself in the back of the train, watched by a very worried Alex, who apparently found it lying unresponsive on the floor of the train and decided it would be better to move it to a safer location. Dave was quite thankful, but it was also very confused.
Why did it even lose consciousness?
Dave didn't really remember what had happened. It tried, but everything from the last hour was strangely blurred and distorted, as if seen through a stained glass window. It had the distinct feeling that it had seen something incredibly horrible in the compartment it was supposed to search, but no matter how hard Dave tried, it couldn't remember what it was.
Well, it guessed it couldn't have been good if it caused it to lose consciousness, so maybe ignorance was a blessing in disguise.
It also turned out that Dave was not the only injured dementor on the train. Apparently, Josh had suffered internal burns from some young female fleshie's 'fire of determination'? Dave wasn't sure if it understood it correctly, but it certainly sounded gruesome.
But whatever it was, it was clear that the train was extremely dangerous! Not only was there some unspeakable horror prowling the train, but there was also an arsonist on the loose!
That was it! Dave was definitely going to make a formal complaint to its superior about the state of the fleshie department! Apparently, they weren't doing their jobs properly if they allowed something so horrible to happen on their train!
This chapter was very... weird to write.
To clarify, Dave reacted this way because it did not see Michael's body. As a conceptual soul-devourer, it saw Michael's soul or the idea of Michael with... everything it entailed.
Also, there is no canonical evidence that the dementors are different from how they are portrayed in this chapter.