He works as an assassin and bounty hunter for hire. His suit was reinforced with an armor that grants him flying capabilities and a boost which allows him to increase his speed, leaving several after-images as he moves around. His weapons of choice are a large cannon in his left hand, and a gun in his right. His left hand weapon can also be used as a flamethrower with a built-in missile launcher on top.
In Strider 2, his armor was completely redesinged, making him even tougher than before. He can release two spinning yellow rings from his shoulders, which will chase Hiryu until they hit him. He still retains his huge cannon, which was modified with two blades on its sides, giving him more firepower.
In the Strider 2014 remake, Solo has lesser armor, which leaves him completely open and defensless against larger attacks. However, he can cover his weakspots with an enhanced flight system, which allows him to fire while flying at high speeds and an energy shield, which protects him from devastating attacks
Solo is a lonely bounty hunter who believes in three things: himself, money and the weapons he's currently holding. He's a ruthless and dangerous killer, who takes pride on being unmatched and will do anything to ensure he gets properly paid after completing his client's request. He seems to be calm and calcuated, always trying to lay down a perfect strategy to utterly annihilate his target.
He also considers himself to be Hiryu's rival, destined to fight him for eternity, but his skills are leagues below Hiryu's level.
In the first Strider game, Meio contraced Solo's services to eliminate Hiryu after he brought down the higher ups at Kazakh. Solo first ambushed Hiryu, as he was making his way through the Siberian Wilderness, but was easily defeated.
Later, in conjuction with fellow assassins, the Kuniang M.A Team (Ton Pooh and her sisters), Solo engaged Hiryu aboard the Sky Thunder MK II, as he was trying to hijack the ship. Hiryu confronted and defeated them all at the same time.
After Hiryu reached the Third Moon, Solo appeared once again for a final encounter against his main rival, but was unable to defeat him and is finally destroyed.
In Strider 2, Solo became the pioneer for a "Superhuman Army" project, whose sucess led to the mass production of the "Solo Type" killer robots. He was hired alongside the Kuniang M.A Team, most likely by the Light Sword Cypher organization, to aid the chinese mafia in an attack on Neo Hong Kong.
Word reached his ears of a single Strider going around the city, defeating everyone that came across his path and he became intrested on seeing what this Strider was capable of. After detecting him on top of the city's whealthy district, he decided it was time to engage. He fought Hiryu in a weaker form, inside a giant satellite dish, but he's easily defeated and retreats to a nearby rooftop. After seeing first hand what Hiryu could do and determined to stop his advance, Solo powered up his armor's energy rings and his weapon to full strength. However, this is still not enough to defeat him, and he is forced to retreat after his armor malfunctioned.
Solo appeared once again to welcome Hiryu at the entrance of the recently built "New Third Moon" base, in company of several of the mass produced "Solo Type" robots, looking for a rematch. Even with the help of the weak gravity in the area, Solo and his army were unable to overpower Hiryu and were destroyed for good.
In the 2014 remake, Solo still acts as an independient bounty hunter. As a man who only believes in himself, his existence could be considered a "shadow" to the Special-A Class Strider Hiryu, who carries out all his assigned missions to their end. Although his services are definetly not cheap, once he's paid, Solo will carry out his request, regardless of how dangerous it might be.
Solo is first seen in a meeting with general Mikiel, where they discuss Hiryu's recent intrusion in the city and the defeat of Pei Pooh. While Mikiel remains confident the Four Winds will defeat him, Solo is certain even if they were to take on him the three of them together, they have no chances. At Mikiel's suggestion he might be worried they would "steal his prize", Solo simply responds he's "awaiting the inevitable" and leaves. Shortly afterwards, he's contacted by Mikiel again. He recieved orders from Meio, who had decided it was time to contract his services, at which he remarks him he should have done that earlier, seeing how "prices have gone up". Mikiel states money is not a problem as long as Hiryu is exterminated, and sends Solo the contract, which is promptly signed.
Solo engaged Hiryu on the Military Ring, unleashing his many weapons and attacks at him, while taking ocassional pauses to either, mock his performance, as he expected better, or laugh maniacally. In the end, Solo is unable to kill Hiryu and was eventually defeated.
That, however, was not the end for him. Through the technical prowess of Meio's Army, the heavily damaged Solo was brought back to life with even more upgrades and weapons than ever, changing his name to Solo ZN-2. These upgrades didn't come without a cost. Having his pride wounded by defeat, combined with the forceful revival process, Solo's mind was slowly starting to rot. His sole purpose was to have his revenge on the strider who made him suffer.
Catching up with Hiryu inside the Balrog's Gravitron chamber, he admits to have underestimated him during their first encounter, but this time, he would kill him without fail. And so began the final battle, which ended up with Hiryu claiming victory over Solo, as his flight system sent him crashing against the Gravitron, bringing down the entire ship down with him