In order to keep rare unicorn possible castmates available with canon, the family he remembers isn't his birth family. An experimental colony of noibats was also attacked when he was very small, and his "family" managed to keep together - only to get destroyed later (five). The remnants of that colony have returned to their original base, which is very far from the edges of Union's tower.

So really out of the way, but vaguely existing in case I manage to attract canonmates-

He would have arrived as a Pokemon in the early time of the kidnappings, and hesitantly revealed himself as a shifter when he could help better help as a human.