Smart, witty, and annoyingly good with kids, Ethan is also a highly observant individual, able to see Battery's trepidation about discussing where her powers came from even though she tried to hide it.
He was one of the heroes who had the best chance of nudging Taylor Hebert toward the Wards program, had he encountered her on her first night out, likely making a neutral, low-pressure offer.
As Madcap, he claimed to stand against everything that the Baumann Parahuman Containment Center stood for, leading into his career as a jailbreak specialist. However, this seems to have been a lie.
As Assault, Ethan wears red body armor with a visor covering the upper half of his face. At one point, when his costume was damaged, he replaced the top half with odds and ends from the PRT's stock costumes.
His costume as Madcap is the opposite; a grinning mask that covered the lower half of his face, and bulky, spike-studded, decorative armour. He had a pointed black leather cap connected to the mask and his costume, and wore black face paint around his eyes. He wielded discus-like throwing weights.
Ethan is a kinetic energy manipulator, controlling the energies of movement, acceleration, and motion, but only on himself and things he touches.
Battery was able to kick off him and leap in the opposite direction at full power without hurting him; in fact, he could use the energy of the impact to move himself at high speeds. He could move over long distances at speeds similar to Chariot, whose suit allowed him to move a hundred miles an hour. He could cross a room with a single leap. He couldn't hit as hard or move as fast as Battery could when charged, but he moved faster than she did on average.
He had a limited ability to resist incoming containment foam, which slid off him more easily than normal. Bugs slid off him as if oiled.
He could deliver kicks that shoved a person across a room without hurting them. He could kick a desk into the air across a room at an enemy.
As Madcap, he used his extremely flexible power somewhat differently.
He could hit an armoured van hard enough to make it roll, or stand in front of one and have it bounce off him, crumpled as if hitting a telephone pole. He could rip the doors off an armoured van. He could rip a weapon from an enemy's hand or smash them against the ground with a touch. He could smash his way through a solid concrete wall without slowing. When Battery slammed him against a wall, he rebounded as if made of rubber. He was able to throw her down the length of a hallway. When he ran, he moved faster with every step. He could make a metal chair that was tripping him crumple and explode.
His power didn't prevent him from stumbling on unanticipated objects, nor make him immune to Legend's kinetic lasers. His power was totally ineffective when he was in midair.
Ethan operated under the name of "Madcap" as a jailbreak specialist. He battled Battery eight times before she finally defeated him, continuously annoying her by calling her "puppy". After he was caught, he joined the Protectorate under the name of "Assault".
His main requirement for joining the heroes was being on the same team as Battery.
As a hero, he continually pestered Battery for a date.Armsmaster struggled to deal with his harassment of her. Eventually, she agreed in exchange for forcing him to help her with community outreach, which she mistakenly assumed he would hate.
Eventually, he and Battery married, though this was unknown to the public; some speculated that he might be her brother.
He was part of a team that battled Lung without success.
His wife was killed by Bonesaw while she was in the company of Skitter, under the influence of Bonesaw's agnosia miasma. He blamed the Undersiders for her death, and pushed for the heroes to be more aggressive against them, even to the point of disobeying orders.
↑I can see Assault, were he to appear on his own, making a sufficiently neutral, low-pressure offer (given his background), but he wouldn't appear alone at a Lung situation. - Wildbow on Reddit
↑“You spent the last five and a half years getting people out of the Birdcage, claiming to be against it and everything it stood for, but now you’re willing to work to put people in there?” - Excerpt from Interlude 12.5
↑Assault – Member of the Brockton Bay Protectorate, a heavy hitter capable of manipulating kinetic energy. Wears red body armor with a visor covering the top half of his face. - Cast (spoiler free)
↑Where their costumes had been damaged, stained or torn, pieces had been replaced from the generic costumes the PRT kept in stock. Miss Militia had doffed the jacket but left the scarf with the flag motif in place. She wore a black tank top and camouflage pants with a number of empty holsters and sheaths for her weapons. Battery was wearing a plain black costume and goggles, while Assault had replaced the top half of his costume with similar odds and ends. - Interlude 13
↑ 6.06.1Two PRT soldiers stepped forward to try to spray him with foam, but he dispatched both with a throw of something that looked like a thick frisbee. With nobody left to stop him, Madcap proceeded to tear doors off the containment vans until he found the prisoners. - Excerpt from Interlude 12.5
↑ 9.09.1<Assault – A kinetic energy manipulator, capable of controlling energies of movement, acceleration and motion relative to himself and things he touches. Was once Madcap, a jailbreak specialist, but was captured by Legend and Battery, and joined the Protectorate. Eventually married Battery. - Cast (in depth)
↑ 10.010.1There's a kid calling himself Chariot. Been racing around the city with a powered suit that lets him move a hundred miles an hour. Assault finally caught up with him last night, brought him into custody. Wound up calling the kid's mom, got him to agree to talk to our recruiter. - Sentinel 9.4
↑"The only ones capable of moving that fast are Assault and maybe Chariot," I said. - Monarch 16.3
↑ 13.013.1She activated her power. Time seemed to slow down as she sped up. She snapped her head to look up and saw him in the middle of a leap over her head. He’d timed it perfectly, so he would be above her when she rounded the corner.
Except she was faster, and she could hit harder than he could. Given a chance.
Her elbow caught him while he was still airborne, and unable to dodge. - Excerpt from Interlude 12.5
↑She covered more distance with the start-stop motion of charging and running than she did just running, but it made for a halting progress where Assault simply continued forward. He made some headway on her. She knew he’d stop at some vantage point to wait for her. - Excerpt from Interlude 12.5
↑I think this would work best if I took on a new identity. New costume. My powers are versatile enough that I doubt anyone's going to draw a connection. - Excerpt from Interlude 12.5
↑Madcap hit one of the armored PRT vans hard enough to make it roll. The driver of the second tried to steer clear, but Madcap stepped into the path of the incoming vehicle. It struck him and the vehicle virtually bounced off of him, the hood crumpling as though it had hit a telephone pole. - Excerpt from Interlude 12.5
↑She wrested the bumper free with a tug and then swung it at Madcap like an oversized bat.
He blocked it with one hand, and the scrap of metal slipped from her hand and went sailing into the nearby cornfield.
Then he slid forward and tapped the flat of one hand against her chest. She bounced off of the ground and fell in a heap. It took her one attempt at standing before she realized it was futile. - Excerpt from Interlude 12.5
↑Madcap leapt to one side as Legend fired a series of beams at him. The villain plunged into and through the concrete wall of the jail, and Jamie was only steps behind him. - Excerpt from Interlude 12.5
↑Her elbow caught him while he was still airborne, and unable to dodge. She slammed him into a wall, and followed up with a leaping kick while the effects of her power still coursed through her.
Madcap rebounded off of the wall as though he were made of rubber and ducked beneath her incoming kick. Twisting around as he rose back to a standing position, he got a grip on her from behind in the same moment her foot hit the wall. Heaving, he hurled her down the length of the hallway. - Excerpt from Interlude 12.5
↑Legend’s lasers tore into the spot where Madcap had been a half second ago. The villain sprinted toward Jamie, moving faster with each step. - Excerpt from Interlude 12.5
↑He turned on the spot, reaching out to block her strike or grab her.
But she didn’t give him the opportunity to do either. Instead, she spent the rest of her accumulated power in a single burst, pulling at the metal of a nearby chair. It fell over, sliding into Madcap’s path. The metal legs caught on his own legs, one sliding just beneath his descending foot. He stumbled. He exerted his power, causing the chair to crumple and explode before he stumbled any further and fell.- Excerpt from Interlude 12.5
↑The Doctor typed something onto the keyboard, paused, and then typed something else. "Madcap. Well, the good news is that he isn't one of ours, so there's no conflict of interest. The bad news is that the PRT rated him as a striker seven." - Excerpt from Interlude 12.5
↑And then there was the team, handling the internal politics, Assault's harassment of Battery, the Wards and their individual issues. - Drone 23.1
↑"See, that's what I don't get. You're a badass, fine. You tested the waters, took on a whole team of local heroes, and you walked away. Right?"
"I fought Armsmaster, Dauntless, Miss Militia, Velocity, Challenger, Assault and Battery," he said. "Yes." - Interlude 22 (Donation Bonus #1)
↑"Armsmaster and Chevalier will be leading the hand to hand combatants who do not fit in Alexandria's group! Anyone who thinks they can harm or hamper Leviathan in close quarters, you'll be assisting and reinforcing the front line!"
Armsmaster strode away from the Undersiders, and I saw Assault, Battery, Brandish, Night and Fog move to join that group, among others. - Extermination 8.2