We know that it struck the arbiter during Legion. And the death of Argus would still be in Legion. And not only that but Argus supposedly was a titan of death. Plus, it seems to me that the thing that struck the Arbiter had the same coloration as Argus in Mythic. As well as the fact that the thing that struck the arbiter came from where the souls come from. A Titan of Death’s soul could possibly be more powerful than the Arbiter herself causing his soul to just end up overpowering her and turning her off like that.
Why would titan soul go to shadowlands though? I thought shadowlands was supposed to be for mortal (as everyone seem to really like to remind us we are one😆)
If that is infact Argus then he is possessing the Arbiter(the Red Soul outright merged with the Arbiter in the Cutscene!) and since he is Red that means Sargeras is possessing him!
Imagine if the Avatar of Sargeras bursts out of the Arbiter and cue the Final Boss!
As for why Sargeras of all people would send Souls to the Maw… He wants the End of All Things so the Jailer who also wants the End of All Things would be the perfect tool for Sargeras to use for that purpose!
I don’t know, but my gut says “maybe”