Did a quick auto run of GOD VIII, IX & X and this team beat all 3 without casualties:

Everyone is maxed but the Gunner Dog

Vampire Hunter Eddie (Immortal/Guard)
Golden Pharaoh Dog (Angel/Energy)
Astra (Energy/Void)
Gunner Dog (Echo/random)

Since I only did one run each I can't say this is 100% safe, but I cleared X in 6:30 and nobody even died during the fight. The power skill priorities seem a bit wacky at times as the GPD didn't use it as often as I would have liked, and sometimes GD would use his healing which is much less effective as the other but mine is unsharded so if you Max out the Gunner Dog you would probably have more healing.