WAG - Harry has never met Justin DuMorne. His Justin was Heinrich Kemmler.

[Bad Alias]

I could see his service as a Warden disillusioning him. He spends his life fighting the forces of darkness only to see the forces of darkness continue to do as they have always done. (I'm not sure that would have been an accurate view after Kemmler was defeated. Eb says some stuff like "you don't know how bad it can be, boy" to Harry at some point that makes me think the White Council has done a much better job than Harry would believe).

I don't see money playing into it at all. I disagree that Harry was having money troubles after he became a warden. Harry basically lies to Murphy when he says his warden salary isn't enough to leave him extra cash to fix his door. It is. He just would rather spend the money on Little Chicago.

I think we can all agree that having limited resources is different than having financial difficulty. I also think we can all agree that covering all of one's necessities, some luxuries, and some savings and/or investments is not struggling financially. Now I won't be surprised it we don't agree that that's exactly what Harry is doing by Proven Guilty. By that point, Harry is covering his rent, keeping the Beetle running, spending a lot on a Little Chicago (which is either a luxury item or maybe a not so great investment in his P.I. business), setting aside sufficient cash to bail someone out of jail with a record in ~2008 Chicago (before criminal justice reform was a thing I'd heard of) for what's likely aggravated battery twice over. I'm going with a floor of $1,500 based on this document http://directives.chicagopolice.org/forms/CPD-11.909.pdf.

Does Harry mention money troubles at any point after Dead Beat? I can't recall any (other than not having any money in Cold Days with having been dead and then in Faerie for about a year).

They don't want to believe that one of their Wardens -- the very ones who keep them save from Warlocks and other Bad Magic -- can turn so evil, and be so undetected.

This. No one who isn't on the receiving end of a law enforcement encounter wants to believe the cops are corrupt.

[toodeep]

Do we actually know Justin's reputation?

I mean, he was obviously known as a very combat-capable Warden (or he wouldn't have been on Kemmler duty)!  Presumably, he shared in the general "Warden" rep -- the greycloaks are kinda grim, very dangerous, implacable, etc...

As far as I know we don't know his reputation, but we do know some things that might be indicative:

1.  Former Warden.  This would probably get him a good reputation with the council, except we don't know if the "former" was his choice or not.  If he "retired" I would anticipate a good reputation with the council, but if it wasn't it may not be.

2.  Apprentice of a Senior Council Member.  This almost certainly would have gotten him in with at least some of the senior council as he would have a powerful sponsor/supporter and good connections.

3.  A known associate (at least to some) to Margaret LeFey.  This should probably have been problematic to most people.  Especially since he was an ex-Warden and the wardens didn't like her.  This may be an indication that he was an accomplished travelers of the Ways, since the Gatekeeper seems to indicate people who are, are something of a fraternity and because of that he knew her too.

Now, we can also assume that some of his Master's reputation might influence him.  Simon was obviously powerful enough that he was on the council and was respected enough that he ran the "brute squad."  The brutes of the squad obviously trusted him enough to serve under him, and the council trusted him enough to let them, and enough to let him be their vampire specialist.  We also know he was also an Ally of Eb's.  BUT, we also know that Eb, as the blackstaff, had to warn him several times for the stuff he was doing near the fall of the Russian Empire so he probably didn't have a sterling reputation.

[Gigglestomp]

At first I read, " he (Kemmler) hopped into Justin, corrupted him, then hoped out went on to someone else," I thought OK, maybe that works, but thinking about it I've got to question that idea too.  It depends on Justin remaining in his own mind but being overwhelmed by Kemmler.  Similar to a denarian taking over the coin bearer's decisions or nemesis taking over one of its victims.  We don't have any indication a necromancer can do this.  Corpse Taker could paralyze Harry and make him forget he was in danger, but she couldn't corrupt Harry or make him think in differently about right and wrong.

So where does this leave the idea of Kemmler jumping into Justin and then moving into someone else?  Well, there is one candidate for him to have jumped into, Elaine.  This might seem like a really nasty twist that would be emotionally devastating for Harry; "Yes, Harry Dresden, when you thought you were killing Justin du Morne you were really killing your first love," but it runs into the same problem of Elaine/Kemmler having more than a couple of decades to plan and pull off a dark hallow and not doing so, and Elaine/Kemmler playing private detective and helping minor magical talents survive the Fomor and other supernatural baddies.  As Mr. Spock would say, "That is highly illogical." (And I mean real ST TOS Mr. Spock, not pathetic emo Star Trek Discovery Spock.)

Think more so what Corpsetaker did to Luccio. She traded bodies with her as she was dieing. I am saying kemmler did something simillar to Justin the day they "Took him out" and since then, and harry's entire life, Justin has been Kemmler-in-Justin's-Meatsuit. Justin was in kemmler's body and died. There is no fight going on internally. He is dead.

[g33k]

Think more so what Corpsetaker did to Luccio. She traded bodies with her as she was dieing. I am saying kemmler did something simillar to Justin the day they "Took him out" and since then, and harry's entire life, Justin has been Kemmler-in-Justin's-Meatsuit. Justin was in kemmler's body and died. There is no fight going on internally. He is dead.

Yeah, but -- as noted -- if Kemmler were alive all those years, there's no good explanation for him NOT going to some massive Darkhallow Hulk-out.  (Never mind the Michigander Indian tribes... let's talk Somme in WWI, or Stalingrad in WWII, running 1 - 2 MILLION violent deaths.  Chang-Ping, with hundreds of thousands of battle-dead and THEN close to a half-million executed prisoners of war.  Darkhallow THAT.)

[Kindler]

I think what turned Justin was learning the truth about the Outer Gates, and realizing What Was Coming, which is why he was looking to mold a pair of Starborn (Starborns? Starsborn?). The only thing we know for sure about Starborn is that they lack some of the weaknesses mortal wizards have against Outsiders.

Based on that, I see three reasons Justin would want that. Either:
A) He wanted to fight them and prevent the Outsider Apocalypse that the series appears to be building toward. This is active opposition to the Outsider Plot.
B) He wanted to suborn the Outsiders and, in some fashion, use their power for himself. I don't know if he thought that Starborn might be able to mentally dominate Outsiders, for example, but I'm sure the idea of enslaving an army of them would have appealed to him if he thought it could be done. Maybe the Starborn would instead have been responsible for a Darkhallow-ish ritual that can only be performed if you can get magic to stick to Outsiders in the first place, and Justin would've legit become an Outsider-level god. Lots of different possibilities with this one that I can see.
C) He wanted Harry and Elaine to be Humanity's Backup Plan. If the walls of Reality crumbled and humanity was about to die off after the Outsiders "won," the two of them would be the seed from which the species could persist. This is the least likely, because I have no clue how Justin would have thought he could have possibly kept the two of them safe if the universe/multiverse was destroyed by Outsiders.

Anywho, I dunno if Justin was planning to fight, steal, or build an Ark. I personally believe he was planning to Steal, and was just dumb about it.

I do go back and forth between Steal and Fight, though. Because if he was really looking to bend Harry and Elaine to his will, he screwed up MASSIVELY, and I can't see Justin being as dumb about it as he was. He basically already had Harry and Elaine on Team Justin. I don't know about Elaine, but I know that Justin was Harry's first paternal figure since Malcolm died. Harry already would have probably done quite a few questionable deeds if Justin had simply asked him. If he had taken just a little more time—a year, maybe, or even six months—he could have manipulated both of them into becoming the thugs everyone claims he wanted.

I've said this before on this forum (well, technically the last one—thanks again, Griffyn), but it's really not that hard to manipulate teenagers. Getting them to do dirty work is easy enough with standard cult-like indoctrination. There's no magic required there; it's all about breaking them down and building them up to your liking. Sadly, it happens all the time in reality—I've known people whom I've tried to help get out of situations like that (sadly unsuccessfully). It is not difficult to accomplish; it just takes time and a complete lack of morality. I've seen young people turn from bright and skeptical to dead-eyed and unshakably credulous over the course of a single year.

I therefore believe that either A) Justin no longer had the luxury of time to accomplish this, and had to rush things for one reason or another (which is compatible with all of the above possible motivations), or B) Justin never intended to turn them into simple thugs in the first place, and what Harry and Elaine went through was either meant for some other purpose, or Justin was no longer in charge. That's really only compatible with the first possible motivation (raising two Starborn to fight the Outsiders), in my opinion. If this is the case, then I think it's possible that the OP is both right and incorrect; Harry did know Justin DuMorne, but the one Harry killed was not the same Justin DuMorne he knew and lived with. I think it is possible that Kemmler OR Nemesis OR Both OR Something Else got to Justin, and possessed/reshaped him such that he was no longer calling the shots.

I'm not saying it's super likely to be true, but I do think it's possible. It would certainly explain my personal hangup about Justin's sudden Kung Fu grip on the Idiot Ball.

[Bad Alias]

(Starborns? Starsborn?)

I vote Starborn as both a singular and a plural. Like deer. How did Justin have a Kung Fu grip on the idiot ball? As I see it, his mistake was not expecting Harry to skip school to check on Elaine. That's about it, unless you count not knowing how to program people through non-magical means.

We should keep in mind that Justin was "dirty" from the moment that he took Bob.

[Mira]

I vote Starborn as both a singular and a plural. Like deer. How did Justin have a Kung Fu grip on the idiot ball? As I see it, his mistake was not expecting Harry to skip school to check on Elaine. That's about it, unless you count not knowing how to program people through non-magical means.

We should keep in mind that Justin was "dirty" from the moment that he took Bob.

   I think it works both ways,  depending on how you use it,  speaking of starborns in general or referring to the starborn in general..  I agree though, Justin didn't count on Harry skipping school to check on Elaine, that was his first mistake..  His second mistake was underestimating Harry's stubborn will, which made enthrallment impossible.   The thought just came to my tired brain.  Harry has always prided himself on his force of will, it has saved his ass many a time.  I've always thought that the strength of his will came from him being a starborn.  Many of us, me included thought that Justin selected Harry and Elaine because he thought one or both might be starborn..  But what that wasn't his motive?  Because why try to enthrall Elaine if she might be starborn because it wouldn't work..  It flat out didn't work on Harry... Then again Elaine still could be starborn and her enthrallment was an act, she seemed to imply that in Summer Knight.

[g33k]

...  I've always thought that the strength of his will came from him being a starborn...

I have wondered that myself.  I concluded it was not the case.

The powerful Immortals, the Mab's & the Fallen &c, clearly know what these "starborn" are.  They have probably dealt with them before... as we see from all the attention Harry gets, being Starborn is significant.  None of the prior ones are likely to have escaped attention from the Movers & Shakers.

If vast & superhuman powers of teh 5tubb0rnz are an inherent Starborn feature, none of these beings would keep presuming Harry had ordinary willpower.
 

[Bad Alias]

But they might be honing and shaping that power.

[Mira]

But they might be honing and shaping that power.

   The fact that Harry will tell her to stuff it when she needs it, is the quality Mab admires most about Harry.

[exartiem]

There was a similar discussion a few years ago.

Here's my theory:  Kemmler body-swaps with Justin just before the killing stroke (Justin is D-E-D dead...).   K realizes that every time he pops up and tries a darkhallow, the WC shows up and kills him.  So he modifies his plan.

He (Kemmler/Justin or KJ) seeks to find or create a Starborn.  Either as a new, more powerful body that can fight off the wardens or as a disciple to fight the WC while he does a darkhallow.  KJ finds Harry or conspires with Margaret to create one.

KJ has the skull.  instructs the spirit to teach Harry but to NEVER reveal that he is Kemmler.  The spirit knows that if it has to answer Harry's questions, there is the possibility it may accidentally reveal what it has been ordered not to.  To prevent this, it creates a separate personality without access to any knowledge of Kemmler for dealing with Harry.  Harry Names this personality Bob. 

Harry has some special power with changing the nature of beings by Naming them (think Lash), add to this the original spirit doesn't have a Name.  This leads to Bob becoming the dominant personality and eventually (on Harry's orders) amputating the original and all of it's proprietary knowledge.

This is when KJ's plan goes awry and has to fake his death again.

[Bad Alias]

KJ has the skull.  instructs the spirit to teach Harry but to NEVER reveal that he is Kemmler.

This could explain why Evil Bob in Death Masks says something along the lines of "I don't know what you'be done with the master."

[Kindler]

I vote Starborn as both a singular and a plural. Like deer. How did Justin have a Kung Fu grip on the idiot ball? As I see it, his mistake was not expecting Harry to skip school to check on Elaine. That's about it, unless you count not knowing how to program people through non-magical means.

We should keep in mind that Justin was "dirty" from the moment that he took Bob.

I count the fact that he went to enthrall them at all as grabbing the Idiot Ball. It was totally stupid and unnecessary, a completely hamfisted approach to getting what he wanted out of a pair of teenagers. Justin has never been characterized as stupid or shortsighted. Enthralling Harry and Elaine is both, in my opinion.

[g33k]

... We should keep in mind that Justin was "dirty" from the moment that he took Bob.

Remember the skull wasn't "Bob" then.

I think secretly taking a magic-knowledge bank of the Evil Necromancer is pretty much a demonstration that Justin was already well-along the Darkside path.

Luccio described it as frightening, and said the Wardens "destroyed it, of course."

Departing from that "of course" wasn't DuMorne's first step down that path!

[Bad Alias]

@Kindler: I disagree. Teenagers are difficult.

@g33k: My point is that he should be categorized as dirty from at least that point. It's not like we know of a single thing he did before that. (He wardened and likely associated with Margaret).