Irony is worked into Ballistic's character, like many of Wildbow's characters. Prior to gaining powers, Luke was friends with all of his teammates and acted as the backbone connecting the other members. However, gaining his powers drove a wedge between him and the rest of the team, and his power itself only lets him destroy.
Interestingly he did not shoot Cherish when he had the chance.  But this was likely the work of Cherish herself.
Ballistic wears a square mask and bulky, angular black armor, with hard-edged pads and pockets holding various ammunition. Both Taylor and Kid Win describe him as having a build like a football player with his costume on.
Underneath his costume, Luke has a jockish appearance, with short brown hair, a snub nose, and a bit of a brow; Taylor calls him "not bad looking."
Luke is one of the offensive powerhouses of the Travelers — he has the ability to imbue any inorganic object he touches, from ball bearings to automobiles, with kinetic energy, causing it to go flying at a bullet-like speed in a direction of his choice, faster than sound.
He does not have to limit himself to small objects, as he can apply the effect to people's clothes and to large objects like cars. Like most of the Travelers he had to be highly restrained and selective with his power to make sure he didn't hurt people.
Luke and his team were preparing for a tournament in his apartment. When the Simurgh attacked Madison, Wisconsin on Earth Bet, she transported several buildings from the same city on Earth Aleph - including the apartment - which left him stranded on Earth Bet with his friends. Luke took a Cauldron vial from a suitcase that Francis Krouse found, giving him powers.
↑Xexilf: Cauldron have been working with this for a long while, and even they only have vague statistics and some hints. If it were as simple as "think of what you want while drinking the vial".... Mentality may play a role. But its far from a clear connection.
Wildbow: There is a connection though. [...] Luke was the pillar of the team, everyone's friend, the glue that held them together. Now he stands alone, and he destroys rather than support. - Post by Wildbow on Sufficient Velocity
↑“I’ll be taking a chair, I think,” someone spoke from the door. Most heads turned to check out a male figure in a black costume with a red mask and tophat. It gave me sort of a Baron Samedi vibe. His teammates followed him into the room, all in matching costumes of red and black, differing only in design. A girl with a sun motif, a guy with bulky armor and a square mask, and a creature so large it had to crawl on its hands and knees to get through the door. It was hard to describe, approximating something like a four armed hairless gorilla, with a vest, mask and leggings in the red and black style its team was wearing, six-inch claws tipping each of its fingers and toes. - Excerpt from Hive 5.1
↑Ballistic – Member of the Travelers, his power lets him turn any touched, inorganic object into a projectile traveling at the speed of a rifle shot. Wears a black costume with bulky, hard-edged pads and a square mask, complete with pockets of various ammunition. - Cast Page (Spoiler Free)
↑Luke was almost the opposite. Grungy, mismatched, dressed in layers, with a plaid green button-up shirt under a blue jacket, and a red t-shirt beneath that. His beard was a thin teenage scruff. He bumped fists with Krouse before sitting down. Krouse was almost embarrassed to realize he was doing something so stereotypically ‘cool’. It had started as something they did ironically and turned into habit. - Excerpt from Migration 17.1
↑Ballistic, Luke (Returned home)– Can accelerate a touched object to a bullet-like velocity in a fraction of a second, from ball bearings to cars. It has been stated/implied by Sundancer that he can’t actually reduce this speed, rendering any use of his power fairly lethal. - Cast List (In Depth)
↑Ballistic was unloading on him with projectiles that moved faster than sound. - Prey 14.4
↑There were capes in Earth Aleph, barely C-list by our standards. Sundancer, Genesis, and Ballistic were there as well, the former two in civilian clothes, retired, the latter in a lavish penthouse, fully done up in costume. My portals opened, and I had control of them. I left Oliver behind. - Excerpt from Speck 30.4