The thing is that they are still immortals. Removing the Destined Death was the removal of the concept of Death from the Elden Ring, which allowed Marika and her Demigods achieve Immortality. The new type of death isn't really something that could be treated as a truth death, if not, then all this movement for removing death wasn't worth at all. Well, I can agree that not everyone has Type 5 Immo, but Marika's lineage surely have. Besides, Destined Death should upscale from the Golden Order (As is something even more primordial and fundamental than it, plus, it has relationship with it), which can kill those who trespass the boundaries of life and death (also I think it works with Those Who Live in Death). And, now that you said that, doesn't mean Destined Death can remove the connection between the Erdtree and the souls, which could potentially be Type 8 Immortality negation? Also, it should be able to kill characters such as Rennala, or some other minor bosses, like the Regal Ancestor Spirit, whose can reincarnate as much as they want.
They aren't immortals of their own volition, nor in the sense that you're presenting them as. Like... consider the context to what you're saying. Removing the concept of Destined Death (as opposed to Erdtree Burial, again, people are still
dying in the Lands Between), fine, cool. Adding it back isn't negation of other types of Immortality, though. It is simply a restoration of the standard order of things. It isn't the same as, say, Sekiro's Mortal Blade. Also I feel you're kind of making baseless assumptions here in saying Marika's new type of Death isn't worth it at all- Marika's intentions are somewhat hard to decipher, mechanically she ensured souls were returning to
her, as she's in the Erdtree. The exact purpose for this I can't say, but it seems significant enough to not be so dismissive of it.
The Golden Order isn't really "primordial and fundamental", but this is mostly a semantics gripe. Things existed before Marika's Golden Order, things will exist after it (Age of Stars, for example, in my game).
I think you're kinda reaching on some of this. Who is immortal based on the Erdtree? Certainly not those in the Lands Between, we've just established that they die and their souls are sent there, that
is the new order of death. You're inventing new types of Immortality based on nothing, as far as I can tell, though if you're just referencing some bits of lore without mentioning it here, do feel free to point it out. In any case, those that
are truly Immortal (like the demigods, as you mentioned) seem to take a long-ass time to properly resurrect. Rykard's head is implicitly going to take a long enough time to revive that Volcano Manor's existence is meaningless in the meantime, so the organization disbands completely. Similarly, Godrick won't be back for long enough that Gostoc is fine ******* with him at the foot at his own throne. So I'd like it known that just because we put such individuals down doesn't mean they are truly dead- just that a return from death in this game seems to take much longer than previous titles.
For the other stuff, I don't know, but your explanation doesn't really negates it's related to destiny, in fact, it potentially supports it (as it's the ultimate outcome, aka, everyone affected by it it's destined to die).
What lmao? I have literally no idea how you're getting that it's manipulating fate. It's like saying I have fate manip for sending a grandparent to a retirement home. Like yeah, that's ultimately where they end up, but I'm not manipulating literal fate to achieve this end. Again, this is pure and utter conjecture on your end.
Yeah, but the thing is, he sealed within him. It wasn't in another part or something like that, he literally used his own body to prevent Destined Death to be unleashed again (that should also make him another Shardbearer now that I think about that haha). The other stuff could be just a game mechanic and such.
Right, so we should see if it works on him. I don't know why they'd make him susceptible to it if he was totally immune to Destined Death, even though we know others of his ilk can die. That seems like a very specific story beat you're trying to argue for. We don't know the exact context or mechanics in-lore of how he seals the Rune of Death away. Assuming he is resistant to it entirely is a leap I don't like the notion of taking.