@moozooh
I'm pretty sure the way gap is used is fairly well known in English as well, though perhaps not quite as well known as other terms like honorifics. Like gap-moe is a fairly popular term.
The impression that I got was that Hecatia was just pretending Clownpiece was her "ace-in-the-hole" and that she just wanted Clownpiece to be safe in a place away from the apparently upcoming power struggles of Hell, while also broadening her experiences at the same time. Eiki also mentioned in...