[SB]Give that...I still ruled ass on sephiroth. He is just a pathetic boss. None of his attacks can actually kill you. They just bring you really ing close to death and those status defects are suppose to finish the job I guess.
I think that wing slash Sephiroth does will do around 6000 damage or so. At level 48, that should be enough to kill you(unless you're stacked with HP Plus Materia).