The phrase "is in power of" can be replaced with a variety of synonyms, depending on the context of the sentence. Some options include "holds control over," "has authority over," "dominates," "governs," "rules," "leads," "manages," "oversees," "supervises," and "commands." Each of these words denotes a level of control and influence, but may have slightly different meanings depending on the situation. For example, "dominates" implies a more forceful and aggressive form of control, while "oversees" suggests a more passive monitoring role. Choosing the right synonym can help to convey a specific tone and meaning within a sentence.