In the end, Sores had successfully persuaded Yalan to join his grand plan to "rebuild the Eternal Fortress."
He didn't directly ask the other person to work for him but, taking Melvin's advice before he left, established an "Eternal Fortress Foundation."
All Contribution Points he earned would be recorded under the name of this foundation and, as the amount reached a certain level, he could apply to Lourdon for city reconstruction projects of varying sizes.
For instance, if restoring the entire Eternal Fortress required one billion Contribution Points, then when the foundation's account had accumulated ten million Contribution Points, it could unlock 1% of the Eternal Fortress's area and begin the construction.
At that time, it was up to Sores himself to select which 1% of the area that would be and to provide the corresponding Blueprint.