Silco was a thin middle-aged man with pale, greyish skin, black hair styled into an undercut, a right blue eye, and heavy scarring on the left side of his face. His most notable trait was his left eye, which lacked an eyelid and appeared to be heavily discolored, with an orange iris and black sclera. He was also generally seen wearing a red and black Piltovan three-piece suit. In his later years, Silco would often wear heavy makeup and several layers of foundation to hide the fact that his facial scarring was slowly growing worse. He also developed an increasing fondness for smoking cigars and gained a grey streak in his hair. Silco was a ruthless and brutal, yet highly intelligent and cautious man who was willing to do anything to carry out his ambitions. He believed that violence was the only way to stand against Piltover and unite the underground against the Topsiders, and that power only came to those who were willing to forsake their own morals to achieve it. His ultimate goal was to free the undercity from Piltover's control and allow it to become an independent Zaunite state under his rule, which he referred to as the Nation of Zaun. Silco held a strong grudge against his former brother-in-arms Vander Vander for betraying him in the past. He also despised the passive leader that Vander ultimately became, believing that the latter had grown soft and weak in his approach against the Topsiders. However, despite his grudge against Vander, Silco still had a degree of respect for him, as he remembered the fearsome fighter that the latter used to be in their youth, and at one point, even offered him the chance to rejoin forces against Piltover. Even after Vander's death, Silco would still hold his old friend in high esteem, as shown when he paid his respects to a statue of Vander that was made in his honor. Despite all his personal faults, Silco had a sense of honor and valued loyalty, as his generation only survived to the present day because of how loyal they were to one another. As a result of this, he had little respect for the chem-barons and viewed them as parasites who take the luxuries that they have for granted and do nothing but leech off the legacies of their ancestors. He also had some level of compassion, as displayed when he embraced and took Powder Powder under his wing after noticing the similarities between her and his younger self. Over the years, Silco would patiently encourage Powder, now known as Jinx Jinx, to pursue her talents and established a close father-daughter relationship with her, ironically echoing the bond that Violet Violet had with Vander. In time, he would come to genuinely care for Jinx as his own child and regularly shield her from the criticisms of his other subordinates, even though he was well-aware of her tendencies as a loose cannon. Although he was typically able to tolerate her wild nature, there were still times when even he would lose his patience with her, as shown when he furiously berated her for murdering six Enforcers and blowing up a building without his permission and seemingly without a valid reason. In the end, the emotional attachment that Silco had for Jinx led him to never give up on her, even when Jayce Jayce offered him Zaun's independence on the condition that he was to turn her over to Piltover.

Self righteous, intelligent, struggles to be affectionate or vulnerable, conflicted, short tempered, straightforward