The phrase "in the character of" is often used to describe the way someone behaves or performs a task. There are several synonyms that can be used to express this meaning, depending on the context of the sentence. For example, one could use the phrase "in the role of" to convey a similar concept. "As" is another common synonym that can be used to describe someone's behavior or actions. Additionally, one could replace "in the character of" with "in the guise of," which implies a certain level of deception or disguise. Other synonyms include "in the manner of," "in the style of," and "like." Each of these phrases can be used to convey a similar meaning to "in the character of".