Talk about a twist. I swear, this manga is giving me trust issues: anyone could turn on Nona and Miramira... By the way, here's a reminder that Miramira blurted Nona's real name out loud last chapter.
I wonder why Mr. Belator quit, since he clearly still has the moves. The most straightforward answer would be guilt, since he clearly doesn't want to bring his past up. More importantly, Raloud seems to be aware of this, which is odd since he has no memory.
Moving into major speculation territory: what if Raloud's necklace is a magical tool, similar to Miramira's shackle, and the reason why it is so important to him is because it is an actual mage? This person could be the reason why Mr. Belator quit being an officer.