Oni Link should definitely be in Super Smash Bros Brawl in some way or another.
I do agree with the people thinking he will be too powerful and no one will ever play as the original Link anymore. That is probably true so I let go of my dreams of playing as him slicing the snot out of a certain McCloud character. Plus I luv Oni Link too much to even picture the idea of a noob picking the character because he looked cool then ending up dying and disgracing the honorable name of Oni Link!
This doesn't mean I will give up on the other reasons why I wanted Oni Link in the game and that is he is just too cool to just be forgotten.
So how will the great Oni Link get into the game? Simple, and no I'm not going to say have him as a super move or an item that everyone can pick up and use. It is very easy actually; have a stage based around him!
Just like the over-hated stage of Bringstar Depths with the huge Craid monster thrashing about put improved and uniquely different. The stage could be made up of multiple platforms and levels, just like the temple stage in melee. The stage floating in thin air would also work with this stage because in this stage, which I officially call (Fierce Deity’s Domain) is in an alternate dimension of the real world. The stage would be eerie looking, distorted, and foggy giving a new element to the stage. The primary colors would be silver, white, blue and black. Secondary colors would be brown for random dead trees in the stage. This stage could also work double as the stage you verse Dark Link in the Event Mode of the game.
In this stage as soon as you enter it you see Oni Link facing his back to the audience in a random spot on the stage that changes every time you play on the stage. Most of the time he would just have his back turned on you and all you get is to see a cool Wii version of the mighty Oni Link. Occasionally he will start to walk and look around and move to a different position (even if it means jumping!). The little twist would be that randomly and 60% of the chance that you approach him or get near to him, he will turn around and attack you!! Even more randomly like say 10% of the time you approach him he not only attacks you but also continues to pursuit and attack you for a little while!!! This will make you avoid him probably most of the time or even force your opponent into his deadly hands! Oni Link would have potential to eventually K.O. if you have enough damage just like those cars in the Earthbound stage. It would be possible to completely ignore Oni Link in this stage and you guys are just meer visitors fighting in his palace but due to his random starting points you would most likely be fighting in a different area of the stage (that is if you don't mind getting sliced or zapped by Oni Link). This really gives a lot of replay value to the stage were as everytime you fight there it's always different. This stage could even possible be bigger than the melee temple stage and on the side note no parts of the stage will be moving or rotating (only Oni Link moves in this stage besides from the fog moving by).
This way Oni Link is still in the game and all his coolness is fully showcased. The only downside of this idea is it's a complete teaser to the audience and they'll be all like, "I wanna play as that guy mommy! Why won't Nintendo let me!! Whaahhh!!" Well for those people, TOO BAD!!! Oni Link is too uber to ever be a playable character and the end result if he is in the game that everyone will be using him as a character, just like how mostly every1 I know uses Fox.
Also to add more of him in there throw in some trophies of him obviously (possibly more than just one!!). I am also okay with having him as a boss much like the Master Hand and GigaBowser, but just like in the Majora’s Mask game he would be a secret unlockable boss!
With that in note my dream can still come true of having Oni Link in the game!!! (just not playable which is the best for all of us)