loyal sidekick
- faithfulConsistently loyal and true
- companionOne who keeps company
- trustyConsistently dependable
- devotedLoyally and lovingly attached
- assistantOne who aids another
helper · Robin · Watson · wingman · squire · ally · follower · deputy · partner · henchman · backup · reliable · steadfast · secondhand · lackey · minion · protector · shadow
loyalty/allegiance
loyal sidekicktraitor
One who betrays allegiance
backstabber · betrayer · turncoat · double agent · Judas
hierarchical role
loyal sidekickleader
One who guides others
hero · mastermind · main character · protagonist · boss
narrative function
loyal sidekickarchenemy
Principal antagonist
antagonist · sworn enemy · nemesis · arch-nemesis · villain