Flawless Freeflow Fighter Achievement
Flawless Freeflow Fighter10
Complete one combat challenge without taking damageThis will either come with practice or patience. Play through the first challenge map "Intensive Treatment" there are less enemies and they won't be armed with any weapons. keep your distance and use some of the tips provided in the videos for Freeflow Gold, they may be for the extreme maps but they will give you some guidance on techniques for taking down enemies quickly.
Make good use of your Batclaw and Batarang, keep evading and watch out for enemies which may attack you from behind.