When it comes to conveying the absence of mercy, there are numerous synonyms for the phrase "no mercy". Brutality, ferocity, pitilessness, mercilessness, and ruthlessness instantly come to mind. These words emphasize a complete lack of compassion, empathy, or leniency. The notion of showing no mercy can also be conveyed through terms like severity, harshness, cruelty, or implacability. Each of these synonyms captures the essence of a firm, unyielding stance that leaves no room for forgiveness or respite. Whether it is in literature, film, or real-life situations, these synonyms aptly describe the unwavering and unrelenting nature of "no mercy."