Man, what in the hell... from Joystiq:
Once summmoned, Shiva has her own commands in battle, making it very similar to Final Fantasy X's summon system. However, Square Enix has introduced a new gimmick in XIII -- the summon's Gestault mode. This is a mode which completely changes not only the appearance of the summoned creature, but the nature of gameplay in battles, as well.
Shiva transformed into a motorbike. The battle system then changed from turn-based to something more suited to an action game. Snow, riding atop Shiva, is able to maneuver around the battlefield in realtime, bashing into enemies and performing certain special skills.
You've got to be fucking kidding me............