I mean you got a bunch of potentially world ending things happening. But 3 seem to jump out. The Darkin, the Void/Frozen Watchers and Mordekaiser.
Nigh-immortal and really pissed off former Ascended.
Alien threat from beyond.
And a necromancer conqueror who has already taken over the world like twice and currently rules some form of afterlife.
So, who do you think is the biggest danger to the world?