• expiatory, placatory, propitial, propitiatory
• implacable, inexorable, irreconcilable, relentless, unforgiving
• implacability, relentlessness
• to conciliate, to placate, to propitiate
• expiatory, placating, propitiative, propitiator
• placation, propitiation
• irreconcilable, relentless