Nothing
On the ground, everyone could do nothing else but watch, open mouthed and pray to whatever gods there be to be on their side and help Zeres regain his sanity and stop this futile battle. The only thing that was making them from losing all hope was the sight of Alexander seemingly enjoying the fierce battle and fighting the demons like a madman. He was like a beast that had at long last being let loose from his cage and now he was enjoying the hunt.
He had tried to destroy Zeres' vortex by calling a very strong wind lance to slash at it, but the wind was swallowed by the blackhole. He tried to reach Zeres too, but Zeres' demons were hell bent in preventing him from coming anywhere close, much less touching their summoner.
At one point, Alexander looked down at where Zeke was standing. And as though there was a wordless communication between them, Alex stopped attacking Zeres and he concentrated on his fight against the demons.
...