I remembered what it was. (I am typing this before reading the new chapter in case I've hit on something that's revealed there.)
Bear with me as this is still half-formed, but... the baddies' argument is that most of the people of the magical world aren't "real", they are soulless simulations.
But...
We've seen Negi essentially make or give a soul to Chachamaru, who worried that she wasn't "real" before. Perhaps that's the heart of Negi's plan -- knowing he'd done it once before for one person, it's just a matter of will and raw power to do it for an entire world's population.
-- Bob
---------
Then the horns kicked in...
...and my shoes began to squeak.
Bear with me as this is still half-formed, but... the baddies' argument is that most of the people of the magical world aren't "real", they are soulless simulations.
But...
We've seen Negi essentially make or give a soul to Chachamaru, who worried that she wasn't "real" before. Perhaps that's the heart of Negi's plan -- knowing he'd done it once before for one person, it's just a matter of will and raw power to do it for an entire world's population.
-- Bob
---------
Then the horns kicked in...
...and my shoes began to squeak.