Basically the key to creating a battle character that doesn't hate mages is to create a reason great enough to warrant killing them as a necessity rather than a pleasure (so to speak).

I had a character called Ogun who had visions of the future in which the overuse of magic had ruptured the veil and caused the coming of the Eternal Night (but who also saw a future beyond it) Think of this like an 'environmentalists' vision of a bad future if we don't stop polluting the planet. One of those environemntalists who happens to be very militant (in the extreme).

Didn't really hate mages, just hated what they were doing to the future. I actually have had several Battle characters who don't specifically hate mages besides Ogun because I hate the whole, 'mages burned down my village so I hate all mages' thing because imho its lazy and boring.

Now whats not as lazy and boring to me but in that vein is 'mages burned down my village because we were unprepared against magic, and now I want to learn to fight mages and rebuild my village with the other survivors so we emerge a stronger village able to protect ourselves from magic'.

In the second one the emphasis isn't on hating mages but learning to protect yourself (and others) from magic. Use your imagination and you can come up with all sorts of viable roles for killing mages that doesnt require you to actually hate them.