Zachery had held back his power ever since he had entered the state of super Einherjar. The power of super Einherjars was too dangerous for this world, and the more he used the otherworldly power, the more detached he would be from the current one; and Zachery didn't want to leave yet.
However cold blooded he had been, ever since he met Wang Tong, he had a taste of what really mattered in this world. He couldn't let go of the memories of the time he had spent with Wang Tong and with Charcoal.
Despite his reluctance in unleashing the power of a super Einherjar, he knew that no one other than him was able to move the city.
