Ranks
Rank 1
Companions gain affinity 25% faster.
Rank 2
Companions have 50 more health and 50kg more carrying capacity.
Rank 3
Companions will occasionally heal you when you get low health.
Rank 4
Doubles the bonuses of Combat and Physical Crew Skills on Companions. Companions have a chance to pick themselves up from a downed state.
Challenges
Rank 1: Sprint 1000 meters with an active follower.
Rank 2: Sprint 2500 meters with an active follower.
Rank 3: Sprint 5000 meters with an active follower.