Help FFXIII: How to beat... (spoilers)

[Marius]

Vanille's eidolon...

So far Im building up his stagger fastest by having both Fang and Vanille saboteurs at the same time. But he is just too strong. Im unable to beat him.

 

[blakstang98]

For most of the battle, I used Vanille as a Saboteur and Fang as a Sentinel. Saboteur builds the Gesault fast, so 2 Saboteurs works very good, but you do have to keep Vanille safe. When I'd have a chance and I figured out the attack pattern somewhat, I would change up to 2 Ravagers to add to the Gesault a little. I imagine 2 Saboteurs works fine too, but you'll want to have Fang as a Sentinel for most of the battle.