I would bring back Brawler's.
Don't have a story yet, but you would play a man in a dystopia/oppressed city, where some area's deemed unimportant are left to the gangs, while the authorities that do intervene do so with highly superior tech and equipment, with no regard for innocent life.
You are outfitted with the Overdrive, a device grafted on your arm, possibly from helping a raid on the Governments facilities. It sends drugs through your system that enhance your reflexes, making time slow, but that's just the start of it. It is slowly repairing and improving you with nanobots. Your becoming faster and stronger and tougher, but there is a limit to how fast you can improve. If you exceed this limit by healing too much... you'll start to find your body stricken with pain, and your powers increasing to the point where you cannot manage them.
In gameplay, you would be from a third person perspective. You would have the standard light attack/heavy attack/sweep/grab combination of controls, but one on one fighting and group fighting would be totally different. Facing off against one gangster would have your fists landing against individual blocks. What we get here is the Turn It System.
Turn It System is a customizable counter system that develops from a simple set of stats you alter. If you faster then most, then hitting the counter button at the right time for a strong opponent will cause you to dodge and land a series of lightning fast counter attacks. But his own Turn It is in strength, meaning that that counter could just as easily land on a strength based counter, padding harmlessly on his chest.
Counters can be countered. Facing off against someone with a similar Turn It suddenly changes to something more akin to The One, or The Matrix, two people of similar skill and move sets locked in a chain reaction of counters, until one of them slips up... and the more counters that happen, the higher the stakes. Simply countering a counter (say, a strength counter verses a speed/stylish counter) would be something like clapping your hands over their head to stun them, then you get a free shot, kick, headbutt, punch, whatever...
But when your in a boss fight, and end up in your 9th consecutive counter... this is when things will get interesting. Your both fast/stylish, the stakes are high, whoever misses this counter is likely dead or crippled (if you have the right stats, high stakes counters can cripple limbs) finally, the boss misses his counter... you begin slamming your palms into his chest, thundering dozens a second, moving him back, until a park bench is behind him... press the kick button, you knee him under the chin, lifting him up, kick him down into the table, straddle his lap and keep palming, your Overdrive kicks in until your arms are just blurs, breaking the table, shaking the ground... and then you slowly stand up. Which button do you press? Kick? Stylish somersault curb stomp finisher.
But if you had lost that counter... that'd be you.
You aren't all powerful though. When the authorities do respond... you're not exactly Superman. Your body is controlled by Euphoria physics, while the land scape is DMM. If your fighting and riot control shows up and you all scatter, and someone shoots you in the chest, your reactive physics kick in. You run, stagger, stumble, eventually collapse behind a wall for cover, and then turn the dial on your Overdrive, and a cloud of Nanites fly out and then spear into the bullet wound. They start painfully repairing the damaged areas, pushing the bullets out, causing you to thrash and groan.
You've just replaced more of yourself with the Overdrives Nanites. You are now more powerful, but more dependent on it. This is fine... once. But spread the Nanites too thin, too fast, and there could be problems (I haven't figured that part out yet)
The only way to fight gun equipped enemies is with surprise and ambush, utilizing the urban environments physics. Watch 3 of them walk into a building? Jump down through the roof to stun them, taking one out instantly, smashing into the two before they can recover and fire. They have backup kicking in the plaster? Shoulder through a wall, get out of there, hide... once they lose you, your on the hunt again.
This is the core gameplay, fighting hordes of henchmen, powerful lieutenants, using customizable move sets, changing your Turn It to your own specific style, and then becoming the urban predator, taking down armed opponents with stealth and then brutal hit and run tactics.
But there's a much bigger fight coming, and you need allies. Fighting these gangs, you free the people from their grasp, but they are still under the Governments heel. This won't stop until you've marched on their doorstep. You inspire followers, and must conduct raids to equip them.
EVERYTHING is customizable... if you can get better guns from a difficult raid, outfit the resistance with them, change their armour, adjust their training, their jobs, get your hand on assault vehicles, modify them, your army will be yours. Your soldiers, your training, your equipment, everything you earned, and you distribute it how you like. And it will matter. You may think you have the best stuff so far... you may not think you need to scout out the other dozens of potential raiding sites, and trigger the revolution. But then you see you were overconfident... you could have trained them better, fed them better, got more and better equipment... you watch your fledgling army cut down, and the game is over.
But if you do put in enough effort, how rewarding would it feel to watch this resistance you built from the ground up steamroll over the oppressors?
This game combines two things I feel are lacking these days. Brawling, and custom built companions.