Potential Spoilers ahead! I couldn't fit it in the title.



Not counting the Calamity, in which they played a major part.

I don't know why I starting thinking about this, but what if we somehow see them again in the far future (like beyond heavensward). This reminded me of one line during the 2.0 storyline where Gaius (I think it was him anyway, it's been a while) compared the Twelve to the Primals. Additionally, we've seen instances of beings that weren't originally primals returning as such (Louisoix, Shive, I think King Mog counts too)

Basically, I was wondering if we will eventually see them return with a greater magnitude to the plot, as potentially primals, either benevolent and malevolent or even just to a lesser extent see them in any capacity.