Brynhildr is fundamentally about staying on top on its first turn, then putting up your typical setup. Tauntaliate is a very valid strategy if you follow Paladin Cecils with Sentinel (see
my post on the matter), otherwise, just the typical mitigation+offense strategy does the job - i.e. Sentinel Grimoire RW, Shellga, Protectga and Breakdowns. You -will- need both Power and Magic Breakdown there, preferrably at R2, but Rydia spamming Blizzaga with your Ice Whip and Cloud spamming Blizzara Strikes (especially under Boost) should be enough on offense to get you by. It's a nasty fight, but it should be doable at your power levels.
Final Fantasy Une Année Sans Autobattle - Still slaving away. Next dungeon brings Faith, which I've been wanting for a while. Kinda ridiculous that it's a 3* ability when its physical Support equivalent (Boost) is a 1*, though.
EDIT: And, since I got a bit inquisitive after Scar, I decided to do a runthrough over my current equipment stack.
6*s (Natural 5*s or otherwise)Diamond Pin (Red XIII weapon, FF7)
Official Ball (Wakka weapon, FF10)
Heat Lance (FF10)
Ten-Gallon Hat (FF8, originally 4*)
Zantetsuken (FF6)
5*s (Natural or otherwise)Judgment Staff (FF5)
Genji Armor (FF5)
Genji Helm (FF5)
Golden Spear (FF6)
Hawkeye (FF6)
Oak Staff (Vivi weapon, FF9)
Monk Robe (FF10)
Royal Crown (FF6, originally 4*)
Emerald Shield (FF10)
Keepsake Knife (FF13)
Danjuro (FF12)
Those are the main fixtures on my builds. I use a few scattered 4* robes and Light Armors (Red Jacket is quite good for a 4*, for example) when I don't have the right equipment draw for a given party composition as well, along with a couple 4* realm-specific synergy weapons like Masamune Blade for FF7 and Warrior Sword for FF10 (in fact, I have a lot of FF10 high-end materials). I suppose I could use better armor in general, but doesn't feel too bad.