"MOMA SUI" seems to mean "They(singular) are/will/should" or "Another person" + "declaration". We don't know if they have "he/she" or only "they". This might double as the plural form if they don't have one.
In this chapter she may be talking to the villager after calling out to Ryuu, saying...
Going with probably not AI. The pin thing is just him using a mirror. The artist does change things a little over the chapters. They seem to add a bow on his back in chapter 2 to represent how much power he's absorbed? In chapter 3 they added a choker. I'd need a few more chapters to really say...