at the same time - this paints Nana in a very bad light, and could easily be used by the 2nd princess as a rallying moment to bolster her own faction's influence via sympathy points.
Daichi wielded the staff immediately before, and nothing happened. Then Nana "the Powerless Saint" touched it and it went haywired and fired on the 1st princess, who was saved by her sister.
Even if this wasn't all "according to plan" (which, we saw #2 tell off Babalus before when the mage was conspiring about ways to cheat #2 into power), it's a fantastic excuse to further malign Nana's position within the Court and draw more people toward herself and Daichi when it comes to backing for Queenship.
I also have to wonder...where did Babalus get a miasma-filled staff, that's ostensibly an important item in its own right for something like a Saint Ceremony as it relates to royal rituals? Is Babalus herself the mastermind behind that, or -- as Alice feared -- is someone else behind her as well, who can control miasma, and is pulling Babalus' strings? If Babalus ends end up being a scapegoat to "tie off loose ends", then the plot continues to grow deeper with agents still moving in the shadows.
But I'm honestly excited that this is getting so deep and involved with the intrigue of the kingdom and going far beyond just "saint and princess go traipsing about curing the world with the power of yuri scissoring". The latter wouldn't have been bad, but it would have been rather...I guess "shallow". This is much more interesting to me, at least.