My battle with Nemesis in FFX HD. I used Rikku, Wakka, and Tidus who all have 255 Strength, Magic, Defense, Magic Defense, Agility, and Luck and base Evasion and Accuracy. For weapons, I used their Ultimate Weapons and they all were equipped with Break HP Limit, Auto-Haste, Auto-Protect, and Ribbon.
I was able to kill Nemesis before he did his ultimate attack Armageddon. I made use of Wakka's Attack Reels overdrive to speed things up.