[Avvesione]

Spoiler:

Well, perhaps with Arclight wanting to see who had a Stigmata, they fed everyone some more Eden Seeds and see who developed what. Maybe that's how characters like Uten were able to develop their Stigmata recently but others (Setsuna) weren't. And maybe that extra dose of Eden Seed put her over the top and is now acting like a toxin in her body (I guess that'd make sense with that evil/demonic looking face she made in the middle of the chapter). Would make sense given how angry she is over not having a Stigmata.

And there's actually one person who comes to mind that could've hit Setsuna at such a speed and not left any sort of wound (well, external or obvious wound). And given how Mio was talking about an angel at the start of the fight, the one who she thought was protecting Cruz, it might actually be ANn or something. Wouldn't that be something?