Originally Posted by
Arafal
Murmur is not an Outland elemental, it got summoned there by the Shadow Council.
And Murmurs actual status is completely unknown, Deaths have never detered anyone from coming back, and that's not gonna suddenly change with some very loosely defined primordial elemental spirit with questionable origin and power.
The little bit we know of it can be easily expanded into more lore and content. (Blizzard has literally made expansions out of less than that)
Especially if they tied it to literally any other current cosmic stuff
Make it some manifestation of the First Ones, or maybe even a Cosmic Pantheon member.
If Dimensius is a sliver of the Void Lords, than Murmur can be a sliver of who knows what else.