Duncan ultimately failed to excavate more memories from his mind.
Although the original owner of this body indeed had concerns for Nina, and things related to Nina were indeed once the most profound memories in his mind, years of illness and the abuse of alcohol and drugs had severely damaged these things. When the heretic named Ron took his last breath, there wasn't much left in his numb brain about the warm memories of family.
There was only one certainty, a fire had truly occurred eleven years ago, right in the Lower City District—it took the lives of Nina's birth parents and forever changed the child's life trajectory.
This might have been a coincidence, but there was also a high likelihood that this incident was actually related to the "Sun Shard" that these Sun Cultists were searching for.