It’s going to be a long while before we have any sort of release date for Diablo IV or anything more than scraps of information from the game’s cinematic reveal trailer. But hey, why not scour that trailer for any indication about the story years in advance? Polish YouTube channel operator TeKo posted a video in which he found editing tags left in the cinematic from the official press kit which hints at the identity of the summoner responsible for the events of said cinematic.
In case it’s not obvious… this is possibly a spoiler, so stop reading if you don’t wanna know.
Two specific editing tags refer to the summoner as Rathma, a specific character from Diablo lore (and the first child of Lilith, which would certainly give him a measure of motivation). Obviously, this isn’t strictly canonical information; it’s not impossible for Blizzard to think that someone might have gone through the editing tags after the fact and thus hidden fake names within to confound people searching for information years ahead of an actual release. It’s just pretty unlikely, especially when “the summoner is Rathma” is a much simpler explanation.