The phrase "at the hands of someone" refers to a person being a victim of someone's actions or behaviors. However, there are other ways to express this meaning through different synonyms. These include "at the mercy of someone," which suggests helplessness and vulnerability, and "subject to someone's whims," which implies that the person has no control over the situation. Other options include "in the clutches of someone" or "under the control of someone," both of which suggest a sense of being trapped or held captive. Ultimately, the use of synonyms can help to highlight the seriousness and potential danger of being at the mercy of someone else's actions.