Emps is not Runescape, we don't have to have the same exact mechanics.
You have not mentioned a single valid reason to nerf the amulet.
Most people at both spectrals and revenants do not use (Full) Slayer Helmets, since they do no bother doing slayer.
Both of these monsters were never meant to be hard to kill.
Also if you were to remove the stacking ability, it would affect every undead slayer monster, not only spectrals and revenants.
You missed my point from the last post. I did not say it is hard and slow, however compared to other skills it is certainly the most time-consuming and requires the most effort put it.
If you really think the combo is too OP for you, why not handicap yourself then? Just don't use one of the items or use lower-tier gear.
Such wisdom... I bow before you, God Saoledpede1. You're truly finding yourself big time here and there in suggestion section. Here is a valid reason, Emps-World, may have it's own content with the additional items brought in game that are its own, but at the end of the day, agree or disagree, if there was no Runescape, there would be no Emps-Scape or Emps-World. Am I wrong?
Now, for your information, I don't intend to copy-paste Oldschool Runescape has and we don't, just to make it more entertaining for myself, suggesting isn't making copy-paste, it's taken into consideration list and then decided if it's meant to be implemented.
I'm write this all for a reason of it being a bit overpowered. If you think, killing revenant in nearly half a minute is fun for you, or should I say "fair enough", then I don't have much to say to you, especially, when I read some topics and you write something like this about players getting multiple rare drops or camping monsters for quite the time: "yeah, they are way too easy to kill or to obtain". Just don't blame me, for invoking items that should maintain their purpose in game and should be reasonable fair for their use, not being something cheap and op, just as dragon darts, having massive dps both pvp and pvm wise dragon daggers, for these, they were always good in both strength and accuracy, or dragon scimitars, which, supposedly have a great chance of turning off prayers, not 100% of doing it. These are few examples of what shouldn't be so good about cheap weaponry or armour, with amulets.
Plus, those most of people, whom you say, don't use full slayer helms with salve, it seems, lately, you haven't been visiting spectrals and revenants too much. They do use both combination to make higher hits - faster kills a trip - maximize exp and profit per trip(recalling, if only task), if not, then they tend to choose salve amulet, because of it being untradeable and not risked, if there were pkers to rush you.
I do understand it will effect most of undead creatures, but seeing hits like ~75 on Spectrals(342 hitpoints or so), makes me wonder, players complain about it being easy, yet they still keep op items to let it be as it is.
10 - 15 % boost would be fine, considering enchantment for more boost could be implemented in Slayer reward shop as well, for fair amount of slayer points. This way, it won't be so overpowered.