Another way to beat zodiac memory- use either girl with behemoth. Max agility and then put alot on power. equip them with grim reaper and deep blue. you'll be freezing him a lot. Grim reaper gives you much needed poison defense and additionally poison damage. He'll get like 5 moves on you. If he's ever not frozen and you're cursed with 1 hp just use behemoth's breath, it gives you temporary immunity to attacks.
If you're having problems with beating zodiac memory make sure you have protection from poison. Either you need a lot of endurance or the grim reaper item. Next it helps have that items or moves that make you invincible for some seconds (behemoth). The 1 health spell zodiac casts stays on your char for like 10-15 seconds and you can't heal. After the spell wears off you can heal yourself. There are several ways to kill zodiac. One way is to constantly freeze him. Another is to use tiamat and a character with maxed endurance. Another is to just blast away with behemoth.
I beat Zodiac memory with Tiamat and Geylan with maxed endurance. This makes soul blossom do a bunch of damage and also gives him poison resistance. For items I used life stream to counter his 1 hp curse move. All you do is keep on using soul blossom and using life stream when cursed or just dodge.