2 Freelancers
1 Summoner
1 Mime

Have the Freelancers with a mastery of Ninja, Ranger, and Gladiator. They will have the innate Dual Wield ability. Give them Rapid Shot and Long Reach, stick them in the back.

Summoner with a mastery of Red Mage. Equip him/her with a Gold Hairpin to cut magic cost down. Equip the Dualcast ability.

Mime will just sit there and Mime the Summoner. Maybe give them a mastery of White Magic so you can save yourself if you mess up.

Both Freelancers should just spam Rapid Shot. They should each down around 7500 - 10,000 damage each round. Summoner dual casts Bahamut. Mime copies Summoner. Combined they should do around 18,000 per round.

I took X-Death down in a round and a half. Neo ExDeath was gone in about three rounds.

One death. Ended the battle with all guys revived and with full health. Didn't even worry about anything.


Edit: Oops. Topic is a tad old. I'll just leave this here if anyone else needs help.