They still have 4 days to swing the NerfBat or apply the Chisel-of-Balance so anything could happen. But what about a Chaos Dragon summoned by Delwynn doing 5 magic damage. IF it hits positions 2-5 thats 5 + 4 + 4 = 13. It's not the potential 18 of Zyvax Vuul but I would think the scenario is a bit more likely maybe except of course that CD is a 14 mana card.
Oh for sure he is nasty too but I'm just saying if all the things lined up who would be able to do the most damage In one hit as unlikely as it is to see it. And think of Zyvax paired with Selenia as well that goes from 18 to 24 😱