Only half of the city was leveled because only that part was exposed to the residual power of the attack. The other part of the city was unscathed simply because it was not in the line of fire.
The part of the city that was leveled disappeared completely. The rubble was pushed some distance away, while the original place in the city had been replaced by a large pit that the tsunami of force had dug up.
Despite how devastating the power of that attack was, it wasn't enough to kill the golden divine being. The Life Fire of the golden divine being was still burning, so he is still alive. What he needs to do now is heal the injury to his body.
Since Loki had attacked him with a rank 6 Divine Metac and an amplification of 100% by his Law Fragments, he would need only 12 years of lifespan to heal the injury to his body.
