Ranks
Rank 1
Boxing
Unarmed attacks do 25% more damage. 25% less O2 used when using a power attack.
Rank 2
Boxing
Unarmed attacks do 50% more damage. 50% less O2 used when using a power attack.
Rank 3
Boxing
Unarmed attacks do 75% more damage. While in a fight and unarmed, running consumes 30% less O2.
Rank 4
Boxing
Unarmed attacks do 100% more damage and have a chance to knock down opponents.
Challenges
Rank 1: Kill 20 enemies with an unarmed attack.
Rank 2: Kill 50 enemies with an unarmed attack.
Rank 3: Kill 100 enemies with an unarmed attack.