MLP and Arpeggio of Blue Steel Crossover
Hasbro and Sanzigen owns the two series~

Escaping their world for survival, four Mental Models merge into one and meet/foalnap a pony for information. But will this meeting change into something more? With a rising shadow from beneath the depths, the Fog might have to enter the raging oceans guns blazing.

But will this encounter destroy or propel Equestria into the future?