key to beating zeromus is not letting anyone die.. because once you do, its very difficult to try to time it so they come back and get healed... and trying to mess with the timing could land you a double big bang which wipes out your party.

80 seems still reasonable to me.... since Z's main attack is so cheap
It would take an incredible amount of lvling to get there, but it seems reasonable.

Perhaps with adamant armor, since it increases all stats 15? maybe Rosa's Cure4 would do more healing enabling lower levels to have a better shot.

That's the only problem with the battle.. its not like Z has alot of HP, its just Rosa can't keep up with the healing on big bang... and he casts it so often.

But in the low 60s, on a low battle speed, you rarely see two big bangs before a cure4, and Rosa's will is high enough to heal enough that you'll last til the end.

PS1 version of course.

Someday I need to lookup the differences between the SNES and PS1 versions...
What makes easytype easy, and hardtype hard.