sidekick

IPA: sˈaɪdkɪk

(informal) An assistant to another person, especially to a superior or more important person.
(authorship, figuratively) In literature, theatre/theater, etc., a good foil of the protagonist, a character who helps emphasize the traits of the main character.

Examples of "sidekick" in Sentences

The hero and his trusty sidekick fought crime together, always having each other's backs
The sidekick was often overlooked, but their loyalty and courage never wavered
With his sidekick by his side, the hero felt unstoppable and ready for any challenge
The dynamic duo of hero and sidekick saved the day once again, much to the delight of the grateful townspeople
The sidekick may not have had superpowers, but their quick wit and resourcefulness always came in handy during a crisis