Arena pack 4 - level 1 "Above Skyscrapers"
The goal of this achievement is to avoid getting hit 6 times, the "Above Skyscrapers" level is the one I got the achievement on.
For this level you are going to try and deflect (almost) every single attack thrown at you. Because of this mission's strong structure damage on deflect modifier you can instantly finish most enemies in this encounter. Not only do you get instant takedowns for most enemies, the enemies here are mostly basic variants.
For larger enemies, you mainly want to try and avoid their grabbing attacks and follow up with your own heavy attacks until you break their stance. Tripping them with sweep is also a great option (sweep: down up Y) You're also going to want to try and avoid getting surrounded, prioritizing weaker enemies as soon as they spawn is a good way of combatting this. The enemies go down pretty quickly even if you don't deflect but I would encourage you to try and use it. I attempted this challenge multiple times and was consistently able to get under 6 hits.
Just stay calm during the fight and deflect when you can. I hope this helps.