He can't match it for power, that's at least a decade away yet, and he really shouldn't be taunting something that could fit his entire body in its mouth with room to spare.

One mistake and even he's going to pay for it.

The temporary change in tactics from the usual bumbling fury he expects of a monster forces Sephiroth to retreat out of the closeness he'd wanted to keep in a sudden backwards leap, the sweep of the massive spiked tail much, much too close for comfort. He has no fear of falling, gravity tended to not work the way it should on him, but being hit with that kind of force...

Unfortunately it puts him out in the open again, and as soon as he has his footing he begins a retreat, not towards the reasonable safety of the rest of Etraya but towards the fortress he really should probably leave alone and drawing on what magic he did have access to without the vast enhancement of materia. Blizzard is a small and weak spell on its own, but cast at the ground instead of the monster, to hopefully make his immediate vicinity terribly slick and a bit jagged, little more than annoying thorns to something a behemoth's size.