It's actually not TOO bad, but you need VERY specific setups to get it done.
First of all, a Paladin is probably a must; light drive is essential. Unguard and Debarrier are essential. Paladin can cover both IF he's got Satellite Beam (although that gets in the way of light drive, slightly).
Healer should focus 100% on healing (and haste/quicken), let the attacker bring Faith; two sources of Esuna would be ideal. Lunafreya can help with earth and wind blasts if you are running Paladin only.
Attacker needs to be dark and juiced (or something else and REALLY juiced). Occultist is best, a properly tuned Solider can do it, Berserker is iffy, but possible. A slow and steady approach will not work as after about ten minutes insta-death Ultima happens.
Last slot can be anything but a Breaker (;_
. A seconder Defender that can drive earth and wind will shield you from all attacks. That on top of additional debuffs means this setup is pretty solid if you lack a supreme card (and the attacker can do the job before insta-death Ultima starts).
The bombs can be a problem. You can survive one (barely), but two is a full failure, even on 3★. Defenders should debuff what they can first (Unguard/Debarrier). Focus on A as the attacker likely has dark attacks. If anybody has an ultimate ready and the yellow gauge can be dealt with, try to break B, that's will kill it.
Light drive before the final attacks to help with Ultima.