OVERVIEW
Director, former Commander, Maria Hill came to his cell. She asked "Why did you come back after escaping?"
Vance ignored her and Agent Daisy Johnson. This gave the illusion that he only listened to mutants when he ultimately answers the questions after a member of the Brotherhood asks it.
The Brotherhood was locked up in the supervillain supermax prison The Vault. Sharing a power set with Victor Creed (AKA Sabretooth) [Vance's father] Vance was held using the same countermeasures to prevent his escape. Hell, they shared a cell. Only the most dangerous supervillains went to The Vault. The select Brotherhood members were held in one cell block, typical for supervillains with such a link as origins to be held in a single block where countermeasures can be custom made.
Vance Creed isn't just Sabretooth's mutant son, he practices black magic. In the back of his neck is a device called a Mystique disk, the device is tied to his mutation and makes him look human. Vance is covered in black sigils. His power comes from a being in another dimension. Only Vance and maybe his twin Vincent can contact the other worlder, Creed has every power imaginable but needs strong mutants to exist on the human plain of existence. Only two mutants are known to be capable of hosting Creed, Vance Creed (AKA Vladimir Michaels) and Martin Hudson [one of Vance's mentors, a paraplegic]. Humans die instantly without harming Creed, mutants burn within minutes due to Creed's presence.
Martin Hudson bore such a striking resemblance to Charles Xavier that Creed was able to use that to access Vance. Creed fell obsessed with Vance. With his powers and Martin as a host, Creed tried to drive Vance to let him in. When physical torture did nothing to Vance, Creed resorted to hurting those around and making Vance watch. He didn't directly use his own powers when a mind controlled inmate could do the job, like Magneto manipulating the metal building to imprison others.
Vance had been temporarily heroic in saving agents during a separate assault but he tried to run to the X-Men soon after Creed started his work. He returned to prevent the psycho from another dimension from killing thousands hunting him. His message to the X-Men got through due to Cerebro. Unfortunately that only gave Creed more leverage. Vance almost let Creed use him again but he helped defeat Creed.
Eventually SHIELD left Vance to Vance, without much choice after he did a massive good deed, superhero stuff. He used his mastery of bad magic to create 3 talismans to contain Creed by controlling Creed's powers. Those kept being stolen from two protectors so Vance had to try taking them back and ended up bringing the third one to the various thieves. A father, brother and sister tried getting the talismans; Vance finally gave up his which overpowered the sibling thieves since Creed is more powerful than an atomic bomb. The father involved helped Vance retrieve the talismans on the condition that he keep them safe. Soon after making the talismans, risking his life by draining himself to do so in the first place, Vance had to destroy them.
The power was too much and too many people, even two mutants from an alternate reality where Creed won came to collect them, Vance had a task ahead of him. He bound himself to the staff the talisman pendants together formed, then hid it in plain sight. He got a special fake book made to hide the small staff from everything that could detect it. He put the book in Charles Xavier's library. He found the tip of the Christian Holy Lance (AKA Spear of Destiny) and hid that sheathed under the library's coffee table.
Vance had many adventures. He flew under the radar, drifting around and working with various underground groups. He was a trusted friend of Aaron Kile. He helped Xavier help mutants escape bad places, similarly joining the mutants' underground (international railroad). All of Vance's adventures meant nothing to him, all he did was help people his way.