The term "powerful effect" can be expressed in various synonyms depending on the context. For instance, the word "impactful" means something that has a significant impact or influence on someone or something. Similarly, "potent" refers to something that has a strong effect or power, while "compelling" means something that is very convincing or persuasive. Another suitable synonym is "striking", which means something that stands out or leaves a lasting impression. "Affecting" refers to something that evokes an emotional response or deeply moves someone. Ultimately, the synonyms for "powerful effect" demonstrate the diverse range of words that can be used to indicate the strength and intensity of an experience or outcome.