Is this guy cheating

[Vyk]

Yes. Master Magic Materia is ONE materia with EVERY spell. So the slots in your weapons/armor don't matter. You should have plenty of room for one materia since you wouldn't have to equip ANY other magic materia after that. I know what you meant. Which is why I said "sets" of spells. i.e. the fire spells, the lightning spells, the gravity spells, etc. There's 20+ sets in the guide. And the dude has one materia that has all of them. Its not cheating. You can get that materia by defeating the Weapons (I forget which one) or make your own by mastering every spell materia in the game. (Note: You can do the same thing with other materia for a master summon materia and master command materia)

[The Devourer Of Worlds]

Emerald has all 3 Master Materia, or more give you an item that gets you all 3 Master Materia.

[Fonzie]

The thing that pissed me off was when he used wall and 2 summons of KoTR and an omnislash didn't kill his ass.

[Captain Maxx Power]

OK let's be mathematical people. Safer has 30,000 by default. If we assume that each slash does around 7k damage, multiplied by 13 this is 91,000, way above Safer's hitpoint range.

[Slothy]

OK let's be mathematical people. Safer has 30,000 by default. If we assume that each slash does around 7k damage, multiplied by 13 this is 91,000, way above Safer's hitpoint range.

He's got 80,000 base HP, plus the 30,000 for each character at level 99, and the 80,000 if you cast KOTR on Jenova Synthesis just to clear that up. There's no way this person has anyone at level 99 or he wouldn't do enough damage on each hit, however, if we assume he's doing 6,800 damage each hit for 15 hits (which was on the low end of how much he was doing), he's still hitting for a total of 102,000 HP. More than enough to kill Sephiroth with base HP. Of course even if one character happened to be at level 99, they could have simply killed Bizarro Sephiroths head a lot to bring his HP down as was said earlier.

The person isn't cheating; it is entirely possible to pull this off.