Silva is a tall, muscular man in extremely good physical condition. He has long, silver-blond hair with blue cat-like eyes, and is always dressed in a sleeveless or short-sleeved shinobi/shōzoku outfit and wears a pair of wristbands.
Silva is a very silent, calm, and pensive person. He has very little interaction with his son Killua, but he does have high hopes for him and has made Killua the heir to the family. Because of that, he raised his son to believe that the only thing sustaining them was darkness, and that the only pleasure in the world came from causing the deaths of others. Silva later allowed Killua to go with Gon on their journey to find his father, but only because he saw it as a crucial step in Killua's development as the heir to the Zoldyck Family.
Silva is Zeno's only son, and was born from an unnamed mother. He's also the only great-grandson of Maha. Not much is known about his childhood, but he was trained since a very young age in the art of assassination, which gave him such abilities such as strong resistance to almost all types of poisons and a high tolerance to electricity. Later on in his life, he married his wife Kikyō, a fellow assassin, and fathered five children with her. At some point prior to the start of the series, he killed an unknown member of the Phantom Troupe and fought their leader, Chrollo Lucilfer.
Abilities & Powers
Being the head assassin from the infamous Zoldyck Family, Silva is extremely skilled in unarmed combat, as he was trained in the art of assassination from a very young age. He also defeated and killed an unknown member of the Phantom Troupe three years prior to the start of the main story, and dueled against Chrollo to an unknown result (both of them survived, though, and in the anime Silva was shown coming back with no visible injury).
Immense Strength: Silva has tremendous physical strength, as demonstrated when he fell from the sky, crushing Cheetu's head with a single blow and creating a large crater, while taking no damage himself. During his fight with Chrollo his punch, although blocked, retained enough power to cause the Phantom troupe leader to lose his balance.
Immense Speed: Killua mentioned that he could rip out somebody's heart so fast that it would not even bleed. He matched Zeno and Chrollo in speed during their confrontation.
Enhanced Durability: Silva's body is more durable than that of a normal human: his skin cannot be pierced by normal blades, and his hair is strong enough to act as a tourniquet.
Immense Poison Resistance: Poison is ineffective against Silva: when Chrollo attempted to poison him by cutting him with his Benz knife, Silva popped the poison out of the cut and resumed fighting with apparently no consequence, although he deemed necessary the application of a tourniquet. Chrollo himself was surprised, because 0.1 milligrams of the toxin he used are enough to paralyze a whale.
Master Hand to Hand Combatant: Silva is capable of gouging out a man's heart with his bare hands and at impressive speed, Killua claiming he can do so without spilling a drop of blood from the wound. He fights using both his arms and legs, harnessing the full strength of his body. When in tandem with Zeno, he puts all his power in his blows at the expense of leaving himself open, knowing that his father will cover him.
Silva can transmute his aura in two large orbs that retain frightening power even after being emitted, showing that he is a top user of this category as well as his own. The fact that he killed Cheetu at close range while creating a large explosion and taking no damage himself, strongly indicates that Silva has also mastered Enhancement. Since Cheetu has feline senses and extremely quick reflexes, it can be inferred that Silva is either capable of mustering a large quantity of aura in an instant or an In user of the highest level, possibly both.