Unfortunately for Sephiroth, he flew right into the Bio spell and flew out coughing hard. Being who and what he was, the poison didn't do any real damage to him, but it was still an incredibly annoying inconvenience. Hacking up a storm while poison nibbled at you was not the way one would like to fight in most cases.

It was then that Sephiroth decided enough was enough. Already he lost the use of his arm temporarily and there was no telling how long that would heal, and now he was being hit constantly with spells? No, no. No more of that.

"Hell's Gate." Once he was within range, he flew up a few feet in the air and swung his sword at a downward angle toward the jester, aiming at head, chest, arms...any place he could think of targeting. He then dropped down to slam Masamune into the ground, where a great fissure split the earth underneath him.