"We have to seal the portal."
Grey and Chris knew their only chance of winning this battle was by sealing the portal so more Gnomes could not come in. Given the initial number of Gnomes present when the battle started and how Grey and Chris quickly killed off more than half of the Ninth stage Sovereigns present, the battle should have turned in their favor already. Yet after killing even more Gnomes, they noticed the number of Gnomes did not decrease, rather, it was increasing. The only explanation was that more Gnomes were trooping in through the portal. At this rate, if another Half God Plane Gnome were to emerge from the portal, then they were as good as dead.
