I will probably regret doing this, but then what is a life without regret, right?

I just finished the last title of the series and, while I really loved the story in general, the ending of Defiance just made me think: "What the hell? This makes no sense."

First of all, how come Kain does not die when Raziel ripped off his heart? And as far as I remember, in BO1 Kain finds the heart of darkness at some point, yet in Defiance he says he never looked for it and apparently does not know he is using it. As he needed Ianos to be murdered in order for him to exist, it makes no sense for me that, even though Kain had access to the time streaming chamber-thingy and knew a lot about his own destiny, he was unaware of Raziel's role in acquiring the heart (SR2, in case you forgot).

Normally I would just ignore this and just accept his "resurrection" as "magic". However, killing Kain was kind of the whole point of Moebius and the Elder God's plans, so it makes no sense that they would overlook the fact that Kain didn't really die after all.

There are many other things which are also unclear for me, but this post is already long enough.

Since they were unable to properly finish the story, the creators answered a lot of questions in interviews:
Kain's nature as the Scion of Balance prevented him from dying and called him back to the Fortress.
Also, and this is my own opinion, he's a vampire. He doesn't need a heart to live. He needed it to come back from the dead and become a vampire, but after a millenium and a half, he doesn't really need it.
In Blood Omen 1 the Hearts of Darkness were a power up that could be used as a medpac or an extra life (if you use it, it' heals you a bit, if you are killed, it restores you). Since, obviously, Janos didn't have 99 hearts (the maximum amount you can acquire in BO1), they were later clarified to be artifacts representing the power of the Heart. Kain really didn't know that the Heart was used in creating him since he thought (as did the players at the time) that Mortanius could just make vampires like he could make any other undead creatures.
As for him being unaware of Raziel's role in acquiring the heart, the fact that Sarafan!Raziel was the one who killed Janos and got the Heart didn't matter to him at the time. The Heart as a whole only started to matter once Wraith!Raziel entered the picture and his actions are impossible to trace.
Moebius dismissed the vampires' prophecy as being delusions of a long gone race, something he did likely because the Elder told him so and the Elder told him so because it was convenient for him.

Do ask other questions, if you have them. I am a giant nerd about the series.

Okay, the pillars calling him back makes sense. As Kain himself says: "I was always considered to be heartless".
And Ianos needed the heart because he wasn't really undead, only cursed with vampirism? How come Wraith!Raziel's actions are impossible to trace? In SR1 it was clearly shown in the end that everything from his fall into the abyss onward was foretold. His actions only became untraceable in SR2 when he refused to enter the Reaver, thus altering history.
Moebius clearly knew Raziel's role in acquiring the Heart, and SR1 and SR2 give the impression that Kain also knew Raziel's destiny and almost everything he did.

And since Kain knew that Raziel would "kill" him (at least before he altered Raziel's destiny in SR2), shouldn't he also know that Razil would rip off his heart and use it to resurrect Ianos? Even though Raziel's moves were unpredictable in Defiance, Moebius says Raziel did what he was supposed to, so I assume resurrecting Ianos with Kain's heart was also supposed to happen.

But I think this point I can kind of accept as a design choice and that a story involving time-travel with 5 titles is going to have one or two inconsistencies. What I still don't get is the next point. As far as I understood, Moebius had nearly omniscience since he was the time guardian. His original plan was something like: kill and turn Kain into a vampire in order to corrupt the pillars. Then use Kain to trigger a vampire hunt, killing almost all vampires. Now use Raziel to kill Kain. Thus, in the end, all vampires would be dead and the Elder God would be pleased. Still, they did not see the part that, when Kain was "killed" by Raziel, he didn't really die. If Moebius did not have knowledge from the time-streaming device, I would accept that he did not predict the intervention of the pillars in keeping Kain alive. But considering the length and complexity of his plans, it feels silly that he wouldn't notice this. It is also weird that the Elder God did not notice that Kain did not return to the Wheel.
He should be able to tell one soul from the other, otherwise he wouldn't be able to turn Raziel into a wraith.

Maybe this was just a design problem: they needed to finish the game within time and so just added a Deus Ex Machina in the end and that's it.

Yes, exactly. SR1 shows that in the end SOME of his actions were well-predicted - his fall, him meeting Kain and destroying the sword - while others never took place or were way different.
His actions became untraceable ever since he got the Wraith Blade. Since the Wraith Blade is his own soul from another time, it made Wraith!Raziel one big walking paradox, free from the Wheel. But, as Moebius said, while Raziel himself is untraceable, his actions still carry ripples, that ARE traceable. Kain knew that Raziel would follow the intended path, but in the original timeline, in which Kain would be killed by Raziel at the William's tomb, he would never succeed at finding the Heart of Darkness: he would kill his former self, get devoured by the Reaver and then it would all repeat. He only became able to find the Heart after Kain spared him from being devoured by the blade and at that point the history was WAY derailed Moebius had nothing to do with Kain being killed or turned vampire; all of that was Mortanius' doing. To counter that, Moebius created the Nemesis out of William the Just and then used Kain to trigger the vampire hunts. He isn't as wise as omniscient as he wants to present himself - also, he's a big, fat liar.
And as it was said, it's likely that The Elder had nothing to do with Raziel turning into a wraith.

Moebius obtains the Heart, which is used by Mortanius to resurrect Kain. So at some point they had to cooperate. They also were the two guardians to oppose the vampires, and Mortanius said that Moebius deceived him, and that he did not know what would really be the consequences of reviving Kain. From this I understood that Mortanius turned Kain into a vampire because Moebius wanted to.
And what do you mean by "to counter that"? Turning Kain into a vampire couldn't hurt Moebius' plans, could it?
Maybe this was explained in BO1, but I played that game a long time ago and was still struggling to follow english dialogue without subtitles, so maybe I missed some details.

Now that I remembered the dialogue with Mortanius in Defiance, is there any explanation what was Durel from the future doing there, before Kain resurrected Sarafan!Durel? (The name is Durel, right?) I think he is too big for the time-streaming chamber... and who would bring him back? True, Raziel mentioned that in SR2. Was there ever a concrete explanation as to why he turned into a wraith? I mean, there are other wraiths in the game, they can't all be related to some ancient prophecy :)

Mortanius explains turning Kain into vampire in Defiance. He wanted to correct his previous mistakes, when he rebelled agains the vampires with Moebius and later killed Ariel (controlled by the Unspoken). He even says that he has set the prophecy in motion, by turning Kain into vampire.

As for Turel from future being present there, he was brought there by lady Azimuth, the planer. You can meet her in Blood Omen 1, but as you mentioned you may have missed some details from that game and she isn't mentioned in Defiance. How did he fit inside the time streaming chamber, I have no clue, maybe he was smaller then.

Raziel turning into a wraith maybe due to the Lake of the Dead that he was thrown into. Its vortex is still present after Raziel comes back. There is no exact explanation, as to why he didn't simply die.

How did Mortanius get the Heart? Moebius took it to the Sarafan fortress and guarded it in order to prevent it from falling in the wrong hands. Did Mortanius invade the fortress? Or did he trick Moebius into letting him guard the heart?

And refresh my memory on one thing: the fact that Kain was murdered and resurrected in BO1 prevented him from assuming his role as the balance guardian, right? Then, in the end of the game, all other guardians are dead and the pillars cannot chose new ones. If Kain sacrificed himself, then the pillars would be able to renew all guardians.
Is this correct?

It's not explained how Mortanius got the Heart of Darkness, maybe Meobius did still trust him. In the end it did benefit him, since it was due to Kain assassinating William the Just that started the vampire hunting. Well, yes and no - what prevented Kain to assume his role was the corruption of the circle that began shortly after Kain was born. When Ariel was murdered her lover Nupraptor the Mentalist (Guardian of the Pillar of the Mind) enraged turned his powers against the other guardians, corrupting them, Kain included. At the end of Defiance Raziel cures Kain from his corruption.

Yes, if Kain would have sacrificed himself, the Pillars would be restored, but the vampires - creators of the Pillars would be extinct. That was his dilemma, the two-sided coin.

I see. It is a shame they had to rush things on Defiance in the end.

There are only two more things bothering me. On Defiance, Kain tried to stop Raziel from obtaining the Heart of Darkness. However, I don't think he said why it would be a problem for him if Raziel did (apart from the fact that he was using it. But he was not aware of this, so he must have had another reason).

Secondly, Vorador appears on BO2 after what happened in Defiance. After Raziel returns to his mansion after taking the Heart of Darkness, Moebius says that he killed Vorador. Was Moebius lying here, or was this a mistake from BO2, since he was definitely killed on BO1.

And thank you both for the answers :)

As far as I remember Kain wasn't aware that he had the Heart of Darkness inside him (the artifact) and was refering to Janos coming back to life and then being the target for the Unspoken/Hylden, but he didn't explain it to Raziel either. He only said something like "a great harm will come of it" when they came across eachother in the Avernus Cathedral.

Moebius did kill Vorador in Defiance, he was repeating his actions from Blood Omen 1. I've read somewhere that there was a scene at the end of Defiance where Kain resurrected Vorador, but was cut, or maybe it was in the unfinished game that was suppused to be a sequel to Defiance. This is the one major plot hole that was supposed to be filled, but unfortunately wasn't.

Always glad to answer anything that's unclear, these games have amazing story (though sometimes a bit confusing) and characters.

Yes, it was clear in Defiance that Kain was not aware of the Heart. I assumed Kain wanted to stop Raziel from resurrecting Janos, but it wasn't clear at all why should Kain care. The Hylden could've used anyone as a target, even Raziel.

Wasn't Vorador decapitated? And I suppose his executioners wouldn't build a mausoleum for him, probably throwing his remains on a pile together with other vampires. I can't picture Kain going through a pile of bodies to resurrect a vampire which he considered pathetic for sitting down waiting for his death instead of doing something about it.
I mean, the fact that Raziel decided to look for the heart could have motivated Vorador to escape Moebius. In Defiance, Moebius only shows Vorador's sword, and he does that in front of his minions. If Vorador escaped, Moebius wouldn't admit it in front of the vampire hunters.

Well, it's what I assumed when Kain said that "great harm will come of it" (the Heart that is), because at the end of Soul Reaver 2 he said after saving Raziel that Janos must stay dead. At that moment Kain acquired new memories (the plot of Blood Omen 2) and knew that Janos will be the target for the Hylden. Unfortunately that message didn't reach Raziel, because he already slipped into the spirit realm. As for why he didn't repeat that when they met in the Avernus Cathedral, I have no clue.

Why did the Unspoken/Hylden choose Janos as their target? Well, he is the last "original" vampire, so it's their revenge and they need someone immortal to "power" thier device.

Yes, Vorador was decapitated in BO1 and it's assumed that the same thing occurred in Defiance. He was the last vampire beside Kain and very old one, so Moebius prepared a public execution for him, which young Kain witnessed after he came back from the past (where/when he killed William the Just): https://www.youtube.com/watch?v=-wpPdQt6DeU

Kain's relationship with Vorador is a bit unclear. He did say that Vorador was a decadent old fool, but Vorador helped Kain when he called for him in the Dark Eden (he dispatched Malek). Plus, Kain kept his ring (as his earring) and in one of the possible endings of Blood Omen (the canon ending) he admits that Vorador was right "We are gods".

Now coming back to Defiance, the old Kain has the memories of Blood Omen 2, so he knows that his younger self will need Vorador and this might be one of the reasons why he would resurrect him. Unfortunately, we might never know whether that was the course of the story after Defiance, it's purely speculations.

As for Vorador escaping Moebius in Defiance, there are no signs other than that we don't actually see him being executed, like in BO1. I assumed it did happen, but there can be other possibilities I suppose.

Vorador's resurrection is technically still unexplained. BO2 was written by a completely different team and as a result introduced many problematic elements into the story. Defiance team was doing as much as they could in cleaning up the mess BO2 left. However originally it was supposed to be Raziel that would resurrect Vorador in Defiance but it was cut.
Source.

I thought BO2 happened after Defiance, and so even old Kain could not know what would happen. Even if he did, he would know that young Kain would defeat the Sarafan anyway, so why bother? Unless he wanted to prevent his first defeat against the Sarafan lord in BO2.

That's not what I meant. I meant that, even if Janos was not resurrected, the Hylden could've used somebody else. But maybe only the Heart would be powerful enough for their purposes.