Legacy of Kain/Fridge

Fridge Brilliance

 * At one point in Soul Reaver, Ariel says, "Those blind with rage are by destiny ensnared." Doesn't that sound a bit like what happens to Raziel more than once?
 * It's even played with, considering one of Raziel's biggest mistakes, killing Kain in Avernus, isn't entirely his doing.
 * Doubles as Foreshadowing if you think of it at the time--when Raziel kills Kain in Avernus, the timeline is perfectly fine, as evidenced shortly after with the pillars shattering. But remember, Kain wielded the Reaver of the past--the reaver that is supposed to absorb Raziel's soul and eventually be wielded by William the Just and then Kain. That Raziel just killed Kain and he and the Reaver vanished, but the timeline isn't destroyed or unravelling, is a clue that Kain isn't really dead.
 * The timeline doesn't get destroyed or unravel in this universe, it just gets rewritten. The Reaver elder Kain has is the broken one from William the Just's tomb, so William has already wielded it and lost to fledgling Kain (who still has his version of the Reaver from BO 1 in Defiance). Raziel is the one that put William's sword back together, and that's when he discovered the spirit within it. Kain is weilding this sword, which presumably already has Raziel's soul inside of it but will also be the sword that will absorb Raziel. This series doesn't seem to have many cut-and-dried answers, especially where the time travel segments overlap and get confusing.
 * Recently I've been rewatching Soul Reaver cutscene where Raziel confronts Kain in the Sanctuary of the Clans. Usually I didn't pay attention to what Kain says, because he's supposed to be a villain in this game, but this time I did - and finally got Kain's motivation to save the world: he feels the weight of the world on his shoulders... and he feels guilty for what has become of Nosgoth.
 * ...Why would you not pay attention to what the villain says? In nearly every game, that would amount to basically not paying attention to the plot.
 * I don't know, maybe because bad guys have tendency to lie all the time?
 * Not really? Most games, especially this series, don't have people on a strict "Evil = lies; good = doesn't lie" continuum. If you just ignore the villain, you're ignoring the game's story nine times out of ten.
 * Definitely, even Janos Audron  Kain, notably, never lies (well, except that time he promised mercy to Sebastian, but when he was called out he made no attempt to keep up the falsehood.)
 * It's actually debatable whether or not Kain was lying when he offered Sebastian mercy; despite his strict honesty, throughout the series people suspect or believe Kain is lying simply because he's Kain. It's likely he knew Sebastian was dying of his injuries anyway and didn't want to waste time arguing the point. It's worth mentioning that Kain doesn't make a move to finish Sebastian off, he simply lets him expire from the wounds he sustained during the fight(most of them being his own damn fault, anyway).

Fridge Logic

 * In the boss fight with Zephon, his spider-form lays eggs, which you light on fire and throw back at him. Okay, typical gameplay. But Zephon was male so why would his spider-form lay eggs... ? Never mind the fact we're later told that Vampires are sterile. It could be that they were cocoons and possibly part of the conversion process for the vampires in his clan. Or they're simply an embarrassing side-effect of his evolution into a giant bug and aren't actually viable eggs anyways.
 * Female birds (like chickens) have been known to "pass eggs" even when there's no male around to fertilize them. There's also asexual reproduction, which is mostly used by plants and single-celled organisms but has also been observed in insects, sharks, and reptiles. Granted, it's usually females that are capable of asexual reproduction, not males, but one of Zephon's devolutions may have resulted in him becoming capable of asexual reproduction even though he's sterile. Also, just because one is sterile doesn't mean reproductive hormones don't continue to be produced.
 * Perhaps that dead vampire hunter in his lair asked him the same question, which is why he was killed.
 * Kain knows pretty much how all of history is meant to play out, and Raziel has the power to change it. Why wouldn't Kain just play it straight with Raziel and explain himself so they can work together to make the world better? Imagine how much more understanding and cooperative Raziel may have been if Kain had taken him aside before killing him and explained the situation to him. "I'm going to have you killed, but ultimately you'll come back to life with the power to change history for the better. Trust me, it'll work out if we work together." Raziel was loyal to Kain prior to his execution after all, he probably would have listened.
 * Well, how would you react if your father said, "Hey, son, I'm going to force you to endure a horrifically painful and humiliating death just before your brothers slaughter all of your progeny and take over your territory, but it's okay, you'll come back as a dessicated blue soul-eating corpse and then we'll save the world"?
 * It wouldn't have worked. Squiddy needed someone who was so royally pissed at Kain that he couldn't possibly have second thoughts about killing him. Raziel is more dangerous than any normal double-edged sword.
 * Kain didn't necessarily know how history was going to play out. Some of the future visions granted to Raziel at the end of Soul Reaver did not play out the way they were shown, e.g. Ariel's absorption at the Spirit forge by Raziel to purify the Wraith Blade in Defiance wasn't as confrontational. The whole problem with Raziel was that no one could see what he would do, all they could see were the ripples he created in history.
 * There's a bit of Twelve Monkeys logic here; Kain couldn't do that because he didn't do that. One of the most notable aspects of Kain's behavior throughout Soul Reaver and Soul Reaver 2 is that he's essentially working off script. Kain knows what he's supposed to do when he's supposed to do it and goes through with it because that's what destiny says he does. It's not until Defiance that you see how Kain acts without knowing what's going to happen ahead of time, as by this point the script has been shredded, burned, and replaced with a whole new play right in the middle of the third act.

Fridge Horror

 * "The Hylden cursed us as they fell." So it seems an entire race suddenly stopped aging. There were probably children who were suddenly not aging, but what about the ones who were pregnant? Did they remain pregnant for the rest of their lives? Did they miscarry? What about the babies that survived expulsion? Wondering how robust the immortal healing factor is, a premature birth might not have been as fatal as it should have been.
 * The pillars choose their guardians at birth; The first guardians were ancient vampires, and judging by the shape of their ghosts, they matured. Still, their immortality may have been different, considering that the human guardians are immortal.
 * The souls Raziel fights are the original guardians, the vampires who actually raised the Pillars. It was only after they died that the Pillars started choosing people from birth.
 * The vampires who were pregnant most likely either had miscarriages or stillborn children, no doubt due to the Elder God's getting angry at them for not being able to die anymore and deciding not to let any more souls become immortal. There wasn't anything that said they stopped aging, it just said they were cursed with immortality; though it is rather curious that the remaining vampires waited until the human guardians were mature adults before turning them into vampires.