We’ve seen how the Eternal Ones seem to be a Soul of some other being, placed into a robotic host to rule over the realms of the shadowlands.
We have also seen the Winter Queen refer to Elune as her sister.
Do you think it’s possible that the Titans wanted to Order Death but only had power to manipulate their own realm of Order and the material realm of Azeroth etc, so instead they made a “plug” in between the Material realm and Death, called the Shadowlands. This allowed them to intercept souls after they died in the material realm and “sort them”.
They possibly required higher beings to caretake the realms of the Shadowlands to which they tasked the Eternal One’s which were originally god-like entities similar to Elune, to rule over the Shadowlands but in order to take form in the Shadowlands they needed a host, which is where the robotic bodies come from?
Elune may have abandoned her role and escaped the SL, which is why the Winters Queen is angry at her.