So there's Aerith, praying beautifully on the altar.

You've got one chance to save her, and if you don't have the right materia, accessories, and limit breaks handy, she's gonna DIE!

Restriction:You can only use materia obtainable on disc 1. And you can only give Aerith materia obtainable before she leaves the party.

Some strategies I've thought of.

Cloud equips a Mastered Cover Materia. Now all we have to do is worry about him surviving!

Cloud equips several mastered speed+ materia and superspeed grabs Aerith and gets her out of the way.

Aerith has lots of mastered Speed+ and Great Gospel available. She uses it.

Aerith has lots of mastered HP+ and a protect ring. 9999 hp+Protect=I'm not dead yet!

Cloud equips several mastered speed+ and has Omnislash available. Carves Sephiroth up while he's trying to descend on Aerith.

You have to remember that Cloud himself was about to kill Aeris. After being under the control of Jenova/Sephiroth he was probably too weak to do anything.

And as for me... I would give barret, or someone else who was watching the entire thing use "Stop" while Cloud was under the control of Jenova and about to attack Aeris, then take them both out of there.

I just wondered why Yuffie didn't throw her shuriken. She's a ninja, the weapon is freaking massive...and she's a NINJA! XD