Valens’s persecution targeted both pagans and Christian bishops.

Evidence

There were vicious persecutions of pagans at Antioch, and on the pretext of eradicating sorcery Valens managed to exterminate practically all the best-known non-Christian philosophers in the Eastern part of the Empire, including Maximus of Ephesus, the man who had turned Julian onto theurgy. — Stephen Kershaw, A Brief History of the Roman Empire, 1678

Categorization

• corroborated: 2 independent passages support this claim — Stephen Kershaw, A Brief History of the Roman Empire, 1678