Beating Vanille's Eidolon !?

Okay, I've finally come to the point where I fight Vanille's Eidolon (too lazy to spell its name), but I must say, he's really kicking my ass. I've had ~5 Game Overs now and I'm getting tired of it.

I usually start with SAB-COM to cast multiple debuffs and whenever the Eidolon starts attacking, I switch to MED-SEN. After each attack, I switch either to MED-COM to heal remaining damage or RAV-COM to attack the Eidolon. Yeah, and that's pretty much everything. I actually never switch back to Saboteur, cause the debuffs stay quite long.

Somehow, I never even come close to filling the gestalt bar. I think I merely manage to fill it 2/3rds, and that's not nearly enough.

Got any hints for me?

Start Sab-Com and when Fang runs up to him immediately switch to Sab-Sen. Doing that means the attacks which affect an area are less likely to hit Vanille because they will be targeted at Fang who is far away. I tend to find that Ravager is slightly faster for raising the Gestalt bar than Saboteur is, but if time is not the issue then go Sab.

It's funny I had trouble with every single Eidolon except this one...

Not bragging, or anything... Um...

If you use Libra, just do what it says. Whatever makes the bar move up more, keep spamming that then the moment Gestalt appears press Square.

You probably already knew that, but I needed to redeem my post!

After another 5 Game Overs, I managed to finally beat him. Vanille was mostly Saboteur during the fight, Medic during/after the attacks and always Fang switched to Commando between the Eidolon's attacks.

Well, I hope I'll get to do another Cie'th quest soon, was only able to finish 2 before I went on.

What helped me was CP farming to get Vanille's extra ATB segment. That way she can support more efficiently.