I'm playing 3 Final Fantasy V at the same time:
SNES version
PS version
and
FFVAdvance
In the SNES version I'm having a hard time with NeoExDeath, he deals a soft damage, but I still don't get what "The laws of physic are broken" means...
I need help please...
Any strategy is good

When he says "The laws of the universe mean nothing", it basically translate to "I'm about to screw you over"...because that's his warning signal for using Grand Cross immediately or very soon. Grand Cross is where he inflicts random status effects on several of the party, sometimes all. This goes from Confusion to Petrification, so be able to remedy all status ailment possibilities. I have yet to see him pull off zombification, but I always kept Angel Rings equipped on my characters, so I never had to worry about it.

Fighting NeoExdeath depends on what you've been working with throughout the game...If you beat Bahamut, Leviathan and saw the scene at the top of the Phoenix Tower, it would help to keep a summoner handy.

If you managed to get some useful Blue and Black Magic (either alone are just fine), then try having a Black /Mage that can use Blue Magic, or better yet, give your Black Mage the ability Dual cast, so they can cast two Flares back-to-back, which saves time and deals some hefty damage.

If you happened to beat Shinryu and pick up Ragnarok, then obviously that's something to give to your Knight to do the physical combat. (NEXD is way easier than Shinryu, so I guess not yet for you...)

And also, if you took the time and awaite the chance of stealing a Dragon Lance (or two) from Crystal Dragons, and you have a dragoon, then stick it on them (It really makes the Jump ability powerful).

I don't recommend the Dancer or many one-at-a-time attackers for this fight, seeing that NeoExdeath consists of 4 parts...each of them you have to destory thoroughly (I never checked, but they should each have about 30,000 HP...so fight quickly and thoroughly)...So here's my recommended party (W/O Ragnarok):

Bartz - Knight - Dual-Wield

Excalibur
Enhancer
Crystal Helm
Crystal Armor
Gauntlets

Reina - Time Mage - !White

Staff of Light
-
Best you have
Best you have
Angel Ring

Krile - Dragoon - Dual-Wield

Dragon Lance
Dragon Lance
Best you have
Best you have
Angel Ring

Faris - Black Mage - Summon

Best you have
-/Best you have
Best you have
Best you have
Angel Ring

(Remember, only keep Summon on you if you have Bahamut, Leviathan and Phoenix...Otherwise, have your Black Mage use Dualcast)

that's a answer....

wear ribbons. be at least lvl 45 i defeated it after a few attempts...shinryu isnt hard

If you want to be really cheap $toss is an easy way out