Cliff Grimoire, grandson of the Milis Church's Pope, was orphaned early by church political strife. Adopted by Harry Grimoire within the Milis Holy Kingdom, his orphanage upbringing fostered a secret admiration for adventurers, leading him to register as one despite his status. Initially marked by extreme arrogance and self-proclaimed genius, Cliff openly looked down on others and struggled socially. During a brief adventuring phase, he encountered Eris Boreas Greyrat. After insulting her and being physically subdued, he developed romantic feelings. Eris rejected his marriage proposal, citing Rudeus Greyrat's superior magic and character, instilling lasting resentment in Cliff towards Rudeus. Seeking refuge from church politics, Cliff enrolled at Ranoa Magic University. His hostility towards Rudeus persisted due to jealousy over Eris's admiration. Their relationship shifted when Cliff requested Rudeus introduce him to Elinalise Dragonroad, an elf he instantly admired. Despite warnings about Elinalise's promiscuous curse, Cliff confidently professed his feelings. His earnest proposal and commitment to researching a cure won her over, and they began a relationship. Academically gifted, Cliff achieved Advanced Rank in Healing, Detoxification, Summoning, and elemental Attack Magic at a young age. His research focused on curse mitigation, developing magic tools that suppressed Elinalise's life-threatening curse for extended periods. He later expanded this work to alleviate Orsted's curse of universal hatred, requiring Orsted to wear a specialized helmet. Cliff collaborated with Rudeus and Zanoba Shirone on the Zariff prosthetic limbs and magic armor prototypes. His expertise in magical circles surpassed even Roxy Migurdia's, earning Orsted's respect. After receiving the Demon Eye of Identification from Kishirika Kishirisu, Cliff wore an eyepatch to cover it. The eye provided object analysis based on Kishirika's knowledge, limited by her awareness. Cliff married Elinalise, and they had a son, Clive Grimoire, who inherited Cliff's appearance and Elinalise's features. Clive developed feelings for Rudeus's daughter, Lucy Greyrat, and they eventually married. Cliff later returned to Milis to succeed his grandfather as Pope. In an alternate timeline, Cliff died during a mission with Rudeus and Zanoba to steal God-ranked detoxification magic from a Milis cathedral, aiming to cure Roxy Migurdia's terminal illness.