Well, I beat every mission and everything in FF13 so I must have. *googles it*
Oh, is it that final mission? I'm pretty sure all I did was spam poison and then chill with everyone as a Sentinel. I thiiiink my party was Vanille, Fang and either Snow or Lightning. I didn't really have many problems with it but the fight took a long time. @_@;
Ugggh hate those things too. :( I think I dealt with them like this?
Step 1 sab/syn/sen: have the sab debuff it while the syn buffs everyone and enthunders (I think it's weak to thunder?) Step 2 rav/rav/sen & rav/com/sen: basically just keep the sentinel out to take the hits from all the other enemies that get summoned. bump up the % with ravagers and pull out the commando every so often to keep the % from dropping.