The easiest way is through subspace emissary, and he comes near the end.
Unlock Sonic
Shadow is only unlockable as an assist trophy in Brawl. He is unlocked as an assist trophy when you unlock Sonic as a player.
There is no shadow the only characters from sonic the hedgehog is sonic
In the cutscene before the final battle with Tabuu, Sonic will appear and shatter Tabuu's wings. Sonic can then be chosen as one of the characters to fight Tabuu, and then you've unlocked Sonic the Hedgehog!
at the end of subspace sonic will appear on the final boss kill the final boss to unlock sonic
Jason Griffith.
You don't, however you can hack Sonic's texture to make him look like Silver.
Well he isn't really a character but he is a assist trophy when you pick up the item you unlock him though by unlocking Sonic the Hedgehog first then shadow is unlocked by a assist trophy
No.
You can unlock Tails, but only as a Trophy.The only "playable" characters relating to Sonic the Hedgehog in Brawl are Sonic (playable) and Shadow (Assist Trophy).Please note that this answer is based upon personal knowledge of the subject.
After unlocking sonic either you can go to coin launcher or the subspace emissary to get the shadow trophy.
I wish you can play as Shadow The Hedgehog as a playable character in Super Smash Bros. Brawl, that would be really awsome. Although you cannot. You cannot unlock Shadow The Hedgehog nor be a playable character in Super Smash Bros Brawl. Although if you unlock Sonic The Hedgehog (playable), you automatically unlock Shadow The Hedgehog as an assist trophy. Also, you can get a Shadow The Hedgehog trophy if you're lucky to find one on the coin launch game. At least you'll have Shadow on Super Smash Bros. Brawl. (But not as a playable character, sorry!) He is playable with hacks. but most of the time it will be some dumb skin hack instead of a psa but if you use a psa you cant play as regular sonic