Wonder what Konp saved MC from in his own mindspace...
We are finally getting some hint to when Shinozaki became a repository, of course is right before the end, the hospital bed makes me think that he was found by granny massively injured and she somehow activated the repo magic to make him a magical being and save his life, the machines weren't thrown in there, they kept him together, alive.
Hard to tell if he was in fact her repository or she forced it as it was the only method she had that could save him.
Nice how niece stayed true to her machines are better than magic and used the stuff in Shinozaki to help her complete the process.
Hope we get the closure we want in the next chapter, the last, but have some doubts...