I don't think it's anything created by the Mastermind - first of all, Asahina-kun has already told us everything that's happened here! Second of all, there's...well, there's a distinct lack of suffering, which I doubt the Mastermind would tolerate based on what she's already done!

[...well, this is Ishimaru not even bothering to save that; if you don't already know, surely you'll ask, right? There's not much sense in concealing it.]

And yes, everyone starts with at least one here; they seem to be our protection here, so it's best to treat them well!