A Glowing Black Pearl - This item is fine and doesn't need changed.
Deception's Laughter - This item is fine and doesn't need changed.
Horok, Reality's Kaleidoscope - This item is fine and doesn't need changed.
Nightwhisper - This item is fine and doesn't need changed.
Voidstep - This item is fine and doesn't need changed.
I think most people are in agreement the procs/focus effects/stats/clickies on these items are in line with the difficulty of the encounter. If the staff wants, I can go more in depth as to why this is, but as of the time of writing the post I think it'd be a wasted effort. Now that we've got that taken care of, we can get to the interesting bits.
Bane of the Fallen God - 1hs Edition. Currently, this item is a stat stick for RNG/WIZ/MAG and it does an okay job at that. Its relatively useful as a stat stick with its +5evo and its flexibility with letting you choose a focus effect or other bonus from your offhand is nice. Its big competitor for WIZ/MAG is Spire of Destruction, which provides DI8 as well as an assload of fire damage and +5evo. For Ranger, this item is an amazing stat stick by providing +5evo which is a very difficult damage boosting stat to cap. It also means you can dual wield, giving you an IMMENSE survivability boost. I think this item is fine as a stat stick for the classes listed. SK/PAL use this item as a weapon, which is where it seems to fall flat. Simply put, Nautilus is better. Nautilus has a better proc for staying alive, as well as +12 riposte mod, meaning its a better choice for pure tankiness on both knights. 1hs Bane only really sees usage on knights in AoE situations due to the proc. Improving the proc in some way might make it see more use for knights, but as it stands its a relatively uninteresting item that sees most of its action in the bags (for knights).
Bane of the Fallen God - 2hs Edition. This item's focus effect is incredibly polarizing. Its existed for a long time with the health cost per cast being 5%. At 10%, this item is unusable for anyone that isn't enchanter. This item is also too strong for enchanter in its current state. The enchanter replacement weapon should be something focused around true giant tome, or some kind of effect similar to Avatar eqlive or a beneficial bard song type ability. To make this item fit its original design intent, I think reducing it back to 5% life per cast is mandatory. Lowering the focus potency from 30% DD boost to 28% would put the item in a good place. It wouldn't make any potential DI9 items irrelevant, while still maintaining its theme of added power for added risk. You have to consider that for wizards, this item makes your burn via flash flame or AoE via jyll's spam far more dangerous due to the fast cast time on these spells. It also "forces" you to give up a DPS boosting wrist proc in favor of NZ bracer. For rangers, it removes your ability to /s 4. That alone is a huge loss of avoidance against melee attacks. Rangers also lose more HP than casters will due to a larger health pool, and they also cannot sustain themselves for a wrist proc. Even in its DI10 - 5% lifedrain iteration rangers did not use this item. For PAL/SK, it becomes a viable 2handed weapon option again and is quite balanced.
The Soul-Shepherd. This item is honestly pretty underwhelming. For CLR/DRU/SHM, it removes you ability to use a Spire of Sympathy, meaning you shouldn't even equip it as an offhand unless you're primarily DPSing or have access to a cella. As far as the clicky goes for those classes, the Blood of the Brood clicky is a stronger alternative for healing. It also removes your ability to bash as a cleric. The soul expansion effect could be changed to last 1 tic longer, or provide a small overhaste, or maybe lower the cooldown by 15 seconds. If you change this item or leave it the same it won't make a big difference. This item is fine for necros in its current state.
Dissonatus, Bladedancer's Bandaid Fix. This item is incredibly strong. +10% aggression on this weapon is a very real meaningful downside to bards. This item, custo sword (custo sword is only good for bards because of 4.3 sword), and blademaster tome are the reasons bards can actually contribute damage at high tiers. Bards have AWFUL damage scaling throughout the tiers. They get AAs to boost their proc rate, but most items have horrible procs so it doesn't matter anyways. This item cannot be changed unless bards are given the song it provides as some kind of clicky or as an actual spell. This item can't be nerfed without giving the bards access to the clicky in some other way or fundamentally changing the class or the entirety of weapon progression. If this item didn't exist, bards would be irrelevant as damage and exist only as support. You'd have very little meaningful ways to scale your damage. This item sucks design wise, but its a bandaid fix that does its job well. If the effect from this item didn't exist for bards, I think their strongest parsing weapon would be an experimental staff of skycalling, or even forgoing weapons to use instruments only. They'd also do significantly less damage in general.
Ysar, Blasphemer's Bite. Draeos kind of sums up my thoughts on this weapon. For being the best known dagger in the game its pretty weak, and given the difficulty jump between this encounter and the 2nd best dagger, it is quite underwhelming. Even "on tier" with this dagger, rogues aren't big dick dps kings like they should be. I think rogues are fine design wise as a class, but for a class that scales very well with its mainhand weapon, it does not have good main hand weapon choices. The easiest fix is improving the base ratio of the weapon. Even if this item is meant to be a stepping stone between the spires dagger and the leaked yael dagger, it does a poor job at it.
Xi Valla Kah. Its hard to discuss this item without discussing the entire clusterfuck of SoD BP progression and the strength of certain proccing BPs. If this items AC gets nerfed hard enough, you'll just see people abusing certain BPs. Unless future BPs have equally strong procs, most classes and smart players will favor lower tier items for their procs. Most classes give up a strong proc in favor of using this item. Honestly, the AC is all this item really has going for it in its current state. If it had CSI9 it'd be appealing to casters again, or even a custom CSI 8.5 focus or whatever. Without the absurd AC, melee's don't really have a reason to use it. In the past it gave worn movespeed, which is a boost to melee DPS on any fight with mechanics that require moving between targets. With the AC nerfed, you could boost the amount of +offense mod on the BP. Its hard to say what'd be an appropriate amount without knowing how much the AC will be nerfed by. Most DPS classes lose some kind of meaningful damage scaling from the BP slot in order to use this robe for physical mitigation. Rogues don't really have any BPs that do this as they get poor spell damage scaling, so giving it stronger white damage scaling isn't a bad choice.
Some of the issues with 4.3 items are just part of a larger issue with itemization as whole. In the case of bards, its a bandaid fix to a class with minimal scaling. Let me know if I should elaborate on anything. I can also draft an enchanter replacement weapon idea, I think a weapon that focuses on improving enchanter true giant capabilities is best as it would have minimal effect on the areas where enchanters already excel and would help resolve one of their glaring weaknesses.