Wow.
Those were sexy images.
Yeah, unfortunately the rest isn't as sexy, IMO. But that's probably because I didn't have to put a lot of effort in it.
Also, MiraiGen didn't say the ability was on all the time, only when that certain ability has been used, and it had a limited time, which would not make Dark Samus overpowered. So yeah, you're a tool.
Anyway, let's go on with the hunters. The main problem with the hunters though is the fact that they so far have only featured in one game. However, they could all work, one better than the other.
Now for every hunter, it would be best to have them use the alternate attack for Down+B. It would work out better anyway. They also have the advantage, like Samus, of being able to dodge roll trough small spaces. Not that it's useful or anything.
Trace has an advantage of being invisible when not moving for a short while. While this is practically useless in Brawl, it should be a feature which can stay. Of course Trace has to use the Imperialist (sniper), a heavy damager, but show to reload. In the time it loads it should also disable other movement. He mostly relies on the Imperialist and his Triskelion form, so most attacks would either be based on the Triskelion or the Imperialist. Because of its claws he could also use some vicous punches to puncture trough armor, but I think that long-distance is more of his specialty.
Weavel has some advantages. His Halfturret is a unique ability, which could come in handy. However, his upper half would be twice as light, so that he could be knocked out quicker. Another disadvantage would be his lower part, which, when attacked, also causes damage. As an upside, his upper side will only get half the damage, or even no damage at all if necessary. So basically, Weavel has two sets of attacks. One as a whole, and one as Halfturret. His blade could be used by both forms, though. His weapon of choice is the Battlehammer, which could also work in Brawl. As a downside, he can't charge the Battlehammer, making it less strong than the other weapons. When holding B however, it will rapidly shoot, and you can control its shooting arc when holding B. It has a very short recovery time.
Sylux has an alternative form, Lockjaw, which could be rather similar to Samus' attack, in which it lays mines. However, these mines won't disappear immediately like the bombs Samus throws, but after a short time, or when three mines get placed. Everyone within the three mines will get shocked. His Shock Coil, another electric-based attack, can be used in various ways, even to ignite a third jump.
Spire's Magmaul could be a powerful fire-based attack. His size could indicate enormous strengths, so he might even get some strong melee attacks. A big problem forms his Dialanche. Its attack is just a bunch of rocks floating around it. However, it could work as Jigglypuff's Rollout, with an added feature of being able to climb walls while the attack lasts.
A cool feature for Noxus is his Judicator, which can litterally ice the opponent. As with Spire, his alternative form, Vhoscythe, would be a melee attack. To make it more unique however, it could somewhat act like Yoshi's Egg Roll in that it will move one direction, but its direction can be changed. Using B during this attack extends his blades, giving him a wider range, and causing knockbacks.
Kanden has a rather useless weapon, the Volt Driver, because it blurs the vision of the opponent. So, to give it some added use, it could just stun the opponent for a very short while. To avoid immediate attacks from Kanden, he has a reload time, which is maybe less short than the stun, but long enough to give the opponent some time to recover. Stinglarva is the hardest one to find something for, seeing as it does drop exploding tail segments, but it's kind of useless. Maybe it could give a short knock upwards.
