With the extra damage and control ability granted by army wide use of Ice Drake Breath, the Echoes manage to hold on for almost two more hours before finally needing to flee from the city, which has received continual high level reinforcements.
Unable to escape on foot, they end up Summoning Dark Phoenix to escape through the void where they're harder to track, coming out a half-hour later with full mana and plans to attack outlying villages instead of big cities. As much fun as it was, it did not succeed in obtaining their primary objective.
Even with the two of them, they were brutally outmatched by that army of Second Advancement transfers. The Area Fire Abilities and turning the very stone of the buildings against them were a nightmare to fight against.
The worst part is that a only one hundred kills separate them in their personal challenge. That's way too close to call a definitive winner.