The characters (that I made up) are:
Zero (I, me, us or anything else that would be said in first person perspective)
Black hair, fair skin, deep blue eyes, never seen without a smile, even if it is just a faint, cocky, I-can't-be-beaten smirk. He fights with his light bow, given to him in the portal by the character only known at the start as 'The Voice', and can fight with his mind as well, drawing energy from objects and using it at will. He prefers to do things on his own, and this can (and will) get him into a lot of trouble.
Final Smash: Arrows of the Elements. A quiver appears on Zero's back containing an arrow of fire, an arrow of water, an arrow of earth, an arrow of air, an arrow of light and an arrow of darkness. He can fire these arrows at any time, even carrying over after a battle. If he still has arrows in his quiver when the move is used again, another six arrows appear in the quiver.
Brian
Blonde hair, sunburnt skin, green eyes. Brian hates Zero, and has anger management issues. He will stop at nothing to destroy Zero, be it with his motorcycle cannon (a dark cannon that he put wheels on), his nebula sword, or a piece of string. He is very powerful, and is likely to charge into a battle on the losing side and come out victorious, no matter who the opponent is.
Final Smash: Dark nebula. The battlefield plunges into deep subspace, making it impossible for anyone but Brian to see. He attacks anyone who is against him with his nebula sword's power greatly increased. This doesn't last very long, because Tabuu can only hold an area in subspace if it was sent there by a subspace bomb, and the nebula sword can only be boosted within subspace.
Iron Oxhide
Dark brown hair on his head, lighter brown fur covering the rest of his body, black eyes, tusks jutting out the bottom of his mouth. Oxhide used to fight as an elite soldier in the subspace army. He was cast out for disobedience during a mission. Tabuu tried to force Oxhide into killing a small boy in cold blood. Oxhide would not. His twin axes (made from iron) are his weapons, used well with his power to control most metals with his mind.
Final Smash: Iron oxide. Oxhide uses his power to pull a pillar of molten iron out of the ground and topple it onto an enemy. Any puddles of molten iron that are still molten are sent flying to a single enemy. This works especially well when fighting enemies that can't stand heat.
Roez (pronounced Reez)
Jet black hair, jet black eyes, jet black skin, jet black personality, jet black bow, pretty much jet black everything. Even his power is black. Manipulating darkness. Sometimes he fights for good, sometimes he fights for the subspace army.
Final Smash: Impure. Roez binds enemies in darkness and makes them want to struggle. The more they struggle, the tighter the darkness gets. Roez can only hold enemies for a minute or two.
The Voice
No one knows what he looks like, who he is, or why he takes kids from earth and puts them into the world of super smash bros.
Final Smash: Unknown, but it is assumed to be very powerful.
Blade
Green hair, hazel eyes, tanned skin. Her hands have been surgically replaced by scythes, and her running speed rivals that of sonic the hedgehog.
Final Smash: Razor wind. Blade runs in circles around an enemy, kicking up dust and making it impossible to see. While running, she slashes the enemy with her scythes.
Cyrus
White hair, very pale skin, brown eyes. Cyrus is Zero's best friend, but he went missing a few weeks prior to Zero landing in the smash bros world. Cyrus had also landed in the 'brawlosphere' as he calls it. He has been living with King Dedede, who had given him a Dedede badge to protect him. Cyrus is running a errand for King Dedede when he is ambushed by Wolf. He is fighting alongside Fox and Falco with his hammer when Zero appears in the middle of the battlefield.
Final Smash: Demolition. Cyrus waves his hammer around like a madman, dealing concussive blows to anyone (including teammates) that are in the way and shattering even the hardest substances like glass.
Lachlan
Dark blonde hair, fair skin, brown eyes. He went missing at the same time as Cyrus, also landing in the Brawlosphere. He doesn't like Zero at all, and the only thing that stops him from joining the Subspace army is the promise that he made to Palutena: That he would help stop Tabuu. He fights with his power to shapeshift into a wolf, as well as his bare hands in human form.
Final Smash: Werewolf. Lachlan's wolf form goes crazy, drastically increasing its power, but also making it likely that Lachlan will attack his teammates.