You mean something like the previous 5 torches that will light the way whisper actually meaning the old gods are the torches and by permanently killing them it will corrupt azeroth? Just look at how pandaria was corrupted, by having all 5 old killed like that might it should be enough to corrupt the titan soul.
old gods being the 5 torches that will light the way for the void lords
Or it might actually mean the world trees since they literally seem to get torched, who knows
I was thinking somethign like that, though we only know about 4 old gods, N´zoth, yogg saron, cthun, ysharj, sorry for the misspelling the names.
so who would be the 5th then, Xalathat, but what I recall she was not an old god, and if there would be a 5th he/she would have to been hidden realy well, unless there is a hole continent we have not seen.
Either Nâzoth or the god of death that Sylvanas is working for.
This could indeed be Calia.
Could either be Sylvanas and her 9 valâkyr in the Shadowlands (do valâkyr simply return to Shadowlands when they die?) or it could be Helya and her valâkyr.
Could be corrupted Meritra of the Dream.
Could be the Titan relics we collected in Legion. Or it could be the Titan facilities. So far we have five known. Uldum, Uldir, Uldaman, Ulduar and the fifth one which MOTHER mentioned.
Could be either Calia, Sylvanas, Helya or Muehzala.