Luís Fróis is a Portuguese missionary and a respected scientist from Spain who traveled to Japan on multiple occasions. In the story of Onimusha: Dawn of Dreams, he functions as both a supporting figure and a secondary antagonist. Originally arriving in Japan to pursue his faith and research, Fróis becomes deeply involved with the forbidden Dark Stone in Kyushu, a project that eventually leads to his possession by a Genma entity named Rosencrantz, one of the three high-ranking demons seeking to resurrect the demon lord Fortinbras. This possession warps his personality and drives him to betray his own beliefs and those closest to him, most notably his adoptive son Roberto, whom he had raised and trained. Fróis’s motivations shift from sincere missionary work and scientific inquiry to serving the Genma agenda, and his descent into madness is recorded in his personal diary, which reveals his growing paranoia and loss of self. In the story, he acts as a guardian figure early on but later becomes a direct enemy, confronting the main characters in his laboratory. His key relationships include his bond with Roberto, which is shattered by his betrayal, and his allegiance to the other Genma leaders. Notable abilities include his deep scientific knowledge, particularly in demonic and alchemical arts, and as Rosencrantz he wields dark magic and can cast a devastating defensive spell known as Doom Clock. His role underscores the tragic theme of a once-noble figure corrupted by the very forces he sought to understand.