A real massive multiplayer online game with leveling, trading weapons, selling weapons, doing quests together. However it wouldn't be a "hack and slash" it'd be a stealth game. It'd take place in the age of Ninja and Samurai, and much like Metal Gear Solid or COD's stealth missions you would have to hide and infiltrate enemy bases. There is no radar or way to indicate when an enemy is near you. You can even get your own temples, houses and marry other players, make families online (Not strictly children and a spouse, but blood-brothers and sisters as well.) You can wall-flip, hang upside down, things like that where the people who pick Samurai get all the heavy armor and heavy attacks, so Ninjas would have to avoid confrontation. You can even get a whole bunch of people and have clan wars. It'd be like a tower defense game but in full 3D graphics, a sand-box open based world, and you'd have to make a clan to help protect your home. But, it'd be for CONSOLES not PC. That's a stretch but someday in the future it could happen.