I can't remember what my levels were when I fought him, but the last 5 million HPs for him was the hardest for me; I hated his deathstrike. Though I do got to say that I found Zodiark a lot more harder than Yazmat.

The last 1.5 million hps of Yazmat's health was destroyed pretty much by Basch single-handedly by using Masamune+Genji gloves with Beserk.