"You carry the same blood as us, it seems. Nevertheless, you're an outsider. Just remember, if you become unpleasant to our eyes, you'll face severe consequences..."
— Chapter 1-2 Ending
Father Bitores Mendez was a Catholic priest whose parish constituted an isolated, rural Spanish community near a castle. Mendez fell to the influence of bio-weapons developer and terrorist Osmund Saddler, who converted people to his cult as a means of control. Fr. Mendez led the initial hunt for USSTRATCOM agent Leon S. Kennedy; Ashley Graham; Dr. Luis Sera and Ada Wong as they made their way through his village, but was ultimately killed as the four made their way into the castle. Some of Mendez's distinguishing characteristics included his imposing stature and trench coat; his artificial left eye; an extraordinary resistance to firearms, and superhuman strength.
Some years before 2004, Fr. Mendez was approached by Osmund Saddler, who desired him as a leader in the community to encourage the conversion of others. Mendez soon shifted to Saddler's cause, becoming a priest for his cult, Los Iluminados,[note 1] and asked the villagers to visit the chapel after the harvest festival. There, Saddler, using Fr. Mendez's trust in him, convinced the people his sermon spoke the truth, that the renown First Castellan was a wicked man and that by being baptised in the way of Los Iluminados, they would be saved. For Fr. Mendez's service, he was given the newly-engineered Dominant species Plaga, which allowed him full control of his body as well as the ability to mutate if needed. Following the successful conversion and parasitisation of the village population, Fr. Mendez was given control over them as Saddler's lieutenant, and was warned of the threat outsiders posed to his plans.
In 2004, Saddler's American mole abducted Ashley Graham, the daughter of the American President, in a plot to eventually release her as a Plaga-parasitised mole. The operation coincided with the escape of Dr. Luis Sera, one of the bio-weapons researchers, who had made contact with another organisation and stolen a Dominant Plaga egg, and there was suspicion this was a planned extraction operation involving the third party. Dr. Sera was captured by the villagers but Fr. Mendez was forced his coordinate his forces against the third party's agent, Ada Wong, and Leon S. Kennedy, a USSTRATCOM agent sent to retrieve Ashley. Mendez succeeded in capturing Kennedy and knocked him unconscious when he freed Dr. Sera. As he was not privy to Saddler's plan to return Ashley, Fr. Mendez was confused by his refusal to have Kennedy executed and instead parasitise him, but nonetheless warned Kennedy he would be killed if he became "unpleasant", fearing he would cause serious damage before becoming a Ganado. After meeting Kennedy, he was attacked by Ada Wong, and had her captured and sent to a cave to be made a human sacrifice.
After an American helicopter sent to pick up Kennedy and Ashley was shot down, Fr. Mendez set up final defences to prevent their escape to the castle. Defences were sixfold: the bulk of the village force was to follow the pair over a suspension bridge and attack a house that could be used as a hideout. Beyond the house were two paths; one containing an El Gigante bio-weapon and another a second, large Ganado force. As the castle required Fr. Mendez's artificial eye to gain access, he based himself in an abattoir on the other side of a Ganado-controlled gondola and, in the event of his death, a final Ganado force was positioned at the castle gate.
In his final confrontation with Kennedy, Fr. Mendez twisted the metal door handles of the abattoir to trap him inside. Kennedy attempted to kill Fr. Mendez by shooting at a barrel of petrol. However, he survived and mutated to have a better chance of survival. His fingernails became elongated, sharp talons; a pair of segmented limbs burst from his back, and his torso was split by a thick, spinal column-like structure edged by tiny, moving legs, greatly increasing his already impressive height. Even severing him below the waist failed to kill him in this form, and in fact increased his mobility; he was able to use the limbs on his back to grab onto wooden beams and fling himself around the abattoir. He was eventually defeated, however and his body incinerated in the petroleum-fuelled fire.