During the war, Cardona and his cell became entangled with a rogue Templar named Rufus Grosvenor, one of the Instruments of the First Will, who intended to have Cardona use the Koh-i-Noor diamond, as Cardona had enough Precursor genes to unlock its powers. This conflict saw him form an alliance with the former Black Cross, Albert Bolden.
He was also an ancestor of the modern day Assassin Charlotte de la Cruz.
Ignacio was raised just outside of Seville. As an adult, he traveled to the Americas and across Europe, wanting to do something to bring justice to the world. At some point, Ignacio became an Assassin and returned to Spain.
Joining the Civil War
When the Spanish Civil War broke out, Ignacio joined the Anarchist movement and supported Buenaventura Durruti, continuing to wear the colors of the Anarchists even after Durruti's death. By then, he became the leader of his cell consisting of his lover Glaucia Acosta, Miguel Carasso and Dwight Adams, an American. In April, 1937, Ignacio and his cell accompanied by several Spanish Republicans made their way to Barcelona. While still a day away from the city, the group set up camp in the wilderness in order to rest.
That night, while sitting around a campfire, Ignacio's companions questioned him about whether his loyalty lied with the Assassins or with them, remarking that since Ignacio and his cell member Dwight Adams were Assassins, it was hard to believe that their presence in the war did not serve some other agenda. However, Ignacio assured them that, although he was an Assassin, he was a Spaniard first.
Shortly after, a member of their group was shot in the head by unknown assailants. Realizing that the assailants were shooting at them from the hills. Ignacio and his group ran up a hill towards them. As he pushed one of the assailants to the ground and prepared to assassinate him, Ignacio realized that the boy and the other assailants were not fascists, but Republicans as well. After Ignacio yelled at everyone to stop firing, the boy told him that they had seen the lights down the hill and had mistaken them for Nationalists, prompting Ignacio to berate them for killing one of their own.
Encountering Norbert Clarke
Ignacio and his cell were facing difficulties and sent a request to the British Brotherhood to send at least a dozen assassins as backup. In May 1937, Ignacio Cardona and Glaucia Acosta hid out among the war ruined buildings in Barcelona. They shared cigarettes whilst they discuss why Glaucia could not sleep, as it turns out she was haunted by a recent bombing raid at the northern town of Guernica.
They were interrupted by a noise, at which point Glaucia let loose several throwing knives at an unknown man in a trenchcoat. Wounded, the man ran to the rooftops with Glaucia in pursuit. She eventually caught up with the two of them coming crashing down through a broken roof. He revealed himself to be Norbert Clarke, sent by the British Brotherhood from London. The Assassins safely returned to their hideout and questioned Nobby as to why he was the only backup that was sent, considering how desperate they are for help. Nobby revealed that he infamously eliminated an entire Templar branch in Tallinn the previous year, which instantly won him the approval of the Spaniards.
Ignacio requested that the team train with Nobby on the rooftop to see his skills firsthand. In the mean time Ignacio ventured out to try and find new weaponry, as their current ones were in a bad state of repair. He met Eric Blair, an Englishman and member of Poum - a Spanish Marxist party. They discussed the way that the class system had reintegrated itself in the city, and how the only items for sale were non-weapons, despite the civil war still raging. Eric had some black market contacts and promised to introduce Ignacio to them. Shortly after entering a shop, gunshots rang out and Ignacio took to the rooftops.
Meanwhile, Nobby and the Spanish Assassins continued to spar on the roof of their hideout, while discussing the split between the anarchists and communists within the community. At this point Ignacio ran past the group, insisting they all follow. They reached a fevered gun battle between anarchists and communists, with the team torn as to who to help with a mind to whom of the two would able to ultimately stop the fascists.
Nobby offered an alternative, telling Ignacio that he could make everyone stop and pulled the Koh-i-Noor out of his pocket. Ignacio stated that he felt it calling to him and touched the diamond. Immediately his eyes started glowing with a blue energy, and serpent-like creatures of energy emerge from the Koh-I-Noor, encircling and wrapping themselves around everyone. Despite blood pouring from his eyes and nose, he found the strength to drop the diamond and passed out. From a nearby rooftop, the Black Cross, Albert Bolden, observed everything that had transpired.
Working with Bolden
Cardona was later taken away by the Black Cross during the commotion to an unknown location. He awoke a while later and was greeted by the Black Cross, who explained that 'Norbert' was using him as a conduit for the Koh-i-Noor and he nearly died because of that. Realising that he was the Black Cross, Cardona attacked Bolden but was easily subdued.
Bolden informed Cardona of his near-death experience in Shanghai and how he had been tracking a Templar named Rufus Grosvenor, who had murdered his family and taken the artifact from him. Grosvenor had somehow taken the identity of Norbert and was looking for someone who would be able to control the artifact, with Cardona himself being a possible target. Wanting to warn his cell and stop Grosvernor, Cardona rode with Bolden along with Spanish revolutionaries to meet him.
A while later, Cardona, Bolden and the revolutionaries found Grosvernor along with the Assassins holed up in a war-torn village. As they made their way towards the village, they were attacked by Carasso and Adams, though they were taken down easily. They said that Clarke had told them the truth and that Cardona had been compromised and influenced by Bolden. In response, Cardona told the Assassins that the Clarke they met was not the real one and that he was working to further the interests of the 'old boss'.
As Carasso drew a gun and pointed at the head of Bolden, Cardona attempted to stop him, saying that it was not their way. Carasso begged Cardona to use the jewel to stop the war. Cardona, however, was unwilling as he could possibly die if he used it again. The two were later interrupted by Adams, who attempted to stab Bolden in the back, leading to a fight between the Templar and the two Assassins.
Cardona on the hand, was held up by his lover Acosta, who had a knife near his neck. He pled with her to stop believing Clarke's lies, though she was already under his sway. Bolden later threw a knife at Acosta, hoping to free Cardona from her graps. However, Cardona stopped the knife, which had pierced through his hand. Acosta revealed she intended to hand her over to Clarke so that he could 'teach' his followers and herself how to become the Instruments. Cardona managed to knock her out with his elbow, thus freeing himself from her. Bolden handed him a cloth so that he could bandage the wound, telling him that if Acosta were to live, her sins would be on his hands.
Cardona and Bolden made their way to the village church, believing that Grosvernor was holding up there. As they entered, they were greeted by Grosvernor who was standing above a mass grave. The rest of the Assassins later arrived and together with Grosvernor, they convinced Cardona to take the Koh-i-Noor and use it to 'save' them.
Despite Bolden's persuasion, Cardona eventually gave in and took the gem, attempting to unleash it. However, the results were not what Grosvernor had expected, as Cardona directed the gem towards him, reflecting that Grosvernor was right and that it was his responsiblity, even if it was for but a moment. Cardona directed the gem towards Grosvernor, unleashing a series of animal-like apparitions which swept across the village and collapsed the church in the process.
Cardona was rescued by Bolden amidst the rubble, informing him that Grosvernor and Acosta had fled, probably to the United States to look for ways to serve their masters, since the gem had been destroyed. Cardona remarked however that the gem was still intact, and only conjured up an illusion to make it look like it was destroyed. He told Bolden that it was now buried in the mass grave deep below the church ruins and asked Bolden what his plans were now.
Bolden told him that since he's the protector of the gem, he would remain in Spain to make sure that the gem would remain in its place and that he would fight alongside Cardona in the civil war. As Cardona asked if he had defected from the Templar Order, Bolden responded that he would never join the Assassins, but he would also not stand alongside the Templars if they were to make common cause with Hitler and Stalin.