What happens when the Akashic Root meets with the branches of the Imaginary Tree?

One day, the stray worldline of Honkai and Herrschers came close enough with that of a certain security organization, appearing as yet another singularity, or perhaps a lostbelt, similar enough to pan human history, yet so different. Regardless, the (un)fortunate souls of Chaldea would need to resolve it, if they wished for their own world to survive.