Eternal Calamity

[Halicor]

So.. I'm at a loss. I've beaten 3/4 of the 999 Colosseum Fights, but Eternal Calamity seems just to be unbeatable for me. I've tried Set-Ups including the 4 CPU-Candidates, buffing them up and trying to rush out the 4-EX Skill which seemed to be the most effective (getting the boss down to 1/3) - before being wiped out by Dragon Raid.
Then I looked up some of the very scarce Guides and Fights and picked up a Party containing Nepgear, Vert, Blanc and Rom. While proving able to flawlessly survive the Dragon Raid - at least as long the Boss doesn't decide to spam it 3 times in a row the I've got practically no means of good damage output against him.
In my last try, which was about 20 minutes long, I wittled him down to again about 1/3 and got instantly hit with Dragon Raid which cost me 2-3 Turns in which I was desperatly trying to save my party. As I was finished.. well.. he helead up to about 1/2 again.

So if anybody has any tipps for this particular fight - I'd very much appreciate it. Or if someone could explain how the Dragon Raid ability works. I couldn't help but notice, that the Dragons prioritize this ability only if they approach below 50% health. But this is very inconsistent.

[darth.crevette]

Use the Neptune/Blanc/Uni/5pb. "infinite turn" trick; more details in this topic:

http://steamcommunity.com/app/351710/discussions/0/598198356199734292/

Even the Eternal Calamity shouldn't do more than his very first attack.

[Halicor]

Thanks! Worked really well! Even though it feels a bit cheap to abuse the Knockback as much as this Party Setup does