These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Big Lipped Alligator Moment: Any time you encounter Wicked K. A zombie in a top hat, who fights with a cane and speaks with the stereotypical high-class British gentleman accent and mannerisms. Appears with no explanation, and disappears after you defeat him each time.
Vigil Games has said that Wicked K is an inside joke, meant to represent a few British employees at the studio.
Cliché Storm: The game has already developed the derisive moniker of "GrimdarkZelda". Or, more specifically, this game is what happens when the Chaos Marines decide to "cleanse" Hyrule, and they sent Kratos in to soften it up.
Game Breaker: Though the Abyssal Armor does take some searching, and you can't get all the pieces until almost the end of the game, it does at that point drastically reduce damage taken, boost damage dealt, and give you a few other perks that make even Apocalyptic difficulty considerably less taxing. And then there's the fact that you can start with it in a new game once you've unlocked it, which would truly make it a Game Breaker.
Chaos Form. Incredible damage and invincibility. It makes any non-boss fight utterly trivial for as long as it lasts, and it doesn't take much effort to refill the rage meter. The second fight against Uriel which would normally be challenging can be ended before Chaos Form runs out.
Death's Blessing upgrade, which gives a weapon (among other good things) an insanely strong life-draining power. You'll most likely never need a green souls chest after you get it.
Affliction spell, which could be more appropriately named "Make Everything Die". It summons a phantom that chases enemies and deals heavy damage to them, and usually lasts long enough to win most fights by itself.
Goddamned Bats: The Goreclaws and Flamecallers, variants of the standard dog-like Minion enemy, which don't show up until the Hollows level. They're very easy to kill, but they do far too much damage for anything that small and they have an infuriating tendency to attack you from either off-screen, or just outside the swinging range of your weapons.
Abaddon broke all but one of the seals in a bid to destroy the forces of Hell without triggering the apocalypse. It didn't work, nor was War amused.
And Samael manipulates War into restoring Samael's power (which is sealed in The Chosen's hearts). He's even magnificent enough to honor his deal with War despite claiming that he could easily kill the Horseman.
The Charred Council given how they lie to War to get him to go after the ones responsible for starting the End War early, and the only reason he even starts acting against them is because of his vision from the Tree of Knowledge.
Most Annoying Sound: In the Black Throne, whenever you're around Azrael, he seems to love to repeat himself over and over again. If you take a few steps away from him and step near him, he will repeat what he just said. Normally this wouldn't be a problem, but there's some platforming that has to happen around him. Inch away even just a bit while you're climbing and he'll repeat himself.
"The beams... redirect the beams... the beams... redirect the beams..." "One last beam, and I will be free. One last beam, and I will be free."
Squick: The Ashlands are a huge desert made entirely out of the ashes of humanity.