Focusing on the role:
* Protagonist is to heroin as clothing is to costume**. A costume is a specific outfit designed to emphasize a role, just as clothing can enhance a protagonist's character or identity.
* Protagonist is to heroin as clothing is to disguise**. While clothing can disguise someone physically, a protagonist's actions can disguise their true nature or motivations, much like a drug can hide underlying issues.
Focusing on the effect:
* Protagonist is to heroin as clothing is to armor**. Clothing can protect us from the elements and other physical dangers, just as a protagonist can be protected by their clothing.
* Protagonist is to heroin as clothing is to expression**. Clothing allows us to express our personality and identity, just as a protagonist's actions can express their values and beliefs.
Focusing on the relationship:
* Protagonist is to heroin as clothing is to accessory**. An accessory is a non-essential item that complements the main object, just as clothing can be seen as an accessory that complements a protagonist's character.
* Protagonist is to heroin as clothing is to reflection**. Clothing can reflect a person's style, personality, and even societal status, just as a protagonist's actions can reflect their values and beliefs.
Ultimately, the best answer depends on the specific context and the message you want to convey.