The answer is unhelpful, but not unexpected. The other shinki he's aware of that recovered memories had similar things to say... whatever the cause might be, it's going to be difficult to figure out just from observation. Add pauses, looking back at the orphanage one last time before following Jakob into the portal. The crack seals shut behind them.

There's some time before they reach the other end of the tunnel. The void surrounding them is dark and endless, broken up by distant black spheres and glittering fragments that look like crystals. They drift in silence for awhile, guided by the faint tug of reality drawing them back in.

"... Some people shouldn't be allowed to have children," Add mutters, staring blankly at a random space in the distance. "But... there are also good parents in the world. Whatever happened to them in the past, they deserve to find a place to belong."

He's referring to the orphans, of course.