Is this guy cheating

[Vyk]

This isn't FF8. Safer Sephiroth has a set amount of HP. And even in the Official Strategy Guide, right before the fight it says "Hint: For a quick win, use Knights of the Round to hit all parts of Sephiroth's body for 70,000 points of damage." Meaning he has 70,000 or less HP. And its a known fact you can get omislash to do more damage than Knights of the Round anyway. And don't you only have to defeat the main part of Safer Sephiroth? Edit, nevermind. That was for Bizarro Sephiroth.

I'm gonna have to watch this video, but I bet there's nothing considered cheating going on.

Okay, that video isn't loading, but I'm looking at the strategy guide. He's using master magic materia with a mastered all materia. There's 20 sets of battle spells you can use, each with an upgrade of one or two extra spells for each set. So yeah. You can have more than 16 sets of spells in battle. That's what Master Materia's about. All spells in one materia. Comes in handy. And a full health (ultima weapon's damage depends on health I believe) with maxed out strength or whatever (I forget what dectates greater attack, 'cause I know just being level 99 and having Ultima Weapon isn't going to give you 9,999 hp damage) doing (almost) 10,000 points of damage 15 times. You get (almost) 150,000 points of damage. KotR does "over 70,000".