Ophidians have a wide variety of warriors in their armies. Perhaps on the lower end you'll have apprentice mages which are very easy to kill, and then up to shamans, justicars and matriarchs that are able to produce powerful spells. For these you'll likely need resist to withstand strong spells. The same can be said for nearly anything that melees but with two exceptions: knight-errants and avengers have a nasty habit of inflicting strong poison upon their foes as well as very devastating hits; avoid these more than anything else. For them you will need some method to cure. Ultimately, if you are running from Ophidians, you will want to avoid those two the most, but be mindful of strong spells from the casters.

Also, get an ophidian slaying weapon.