All credit goes to Russel
The l'Cie you fight in this chapter is a real pain, the following guide works like a charm
"Use Lightning, Snow and Sazh. Set up a Paradigm for Med/Sen/Syn, one for Rav/Rav/Rav, one for Com/Com/Rav and one for Med/Sen/Rav. Make sure that in your two Commando Paradigm that you have Snow as your other Commando since he should know launch by now. Use a Fortisol, before you start the encounter and use Med/Sen/Syn to begin the fight. The key is to not damage him until you really want to lay waste to him. Once all your buffs are up, I think you can do this without the Fortisol, it will just take a little longer of Sazh putting up buffs, switch to Com/Com/Rav for at least one round to get your stagger meter up a little. Then switch to Rav/Rav/Rav and give him hell. When you get someone low on health, switch to Med/Sen/Rav and heal up, make sure you keep at least a Rav on him and don't heal for long then switch back to Rav/Rav/Rav. You want to avoid letting him transform which he will do after a certain amount of damage, not time. Once you get him staggered, immediately switch to Com/Com/Rav and kill him. You have to stay on him, but with two Commandos you should be able to keep him in the air the whole time. This method should kill him in one stagger and he will never transform. I was just like you and searching for a way to kill him and found one person who recommended this among lots of other people with long drawn out fight sequences, figured I'd try it and I killed him in 2:22. Good luck"