since this is both villain forms, they’re probably going to carry out this plan together. As to the wineglass, and the fancy dress, there’s a myriad of reasons she could have it. (the reason is i wanted to use a dress up game to put Eas in an evening gown, but we’re talking in-universe here). Maybe the glass is part of the evil plan. Maybe this is actually Setsuna, who retained her old powers in this version, and changed into that form for whatever reason before dressing fancy for some kind of high-stakes bargain game. (in which case this is probably a trap which Setsuna is now caught in)