Behemoth are one of the more-challenging of the monsters of Crystallis and that was before the corruption of the Calamity had been released from the natural protection of crystal. Sephiroth recalled partaking in a bounty hunt specifically for a behemoth, before, at the time that Mysidia was still such a new continent to them. It had been a matter of personal satisfaction then; considering he often used to hunt down behemoth on his home world, almost as a hobby.

Of course Sephiroth couldn't turn down the opportunity to pit himself against the Calamity-variant of that particular beast and so had teleported with Akane for this particular jaunt.

He'd hung back and let the others encounter first, out of a desire to gauge the beasts potential intelligence before charging in sword-first. It seemed as invulnerable as Sephiroth imagined it might be, at least. As Akane shouted to scatter while the Behemoth continued to charge, a sturdy hand reached back and down to release the handle of his over-long sword from the straps that kept it in his custom harness.

The reassuring weight of old-faithful; Masamune, dropped into his grip and was smoothly pulled from its sheath. Sephiroth didn't even seem to blink though, remaining still enough of a distance away so as not to be so obviously a member of the same party; especially to such a raging beast.