User blog comment:The Pop Cult Gamer/More Sonic characters for Super Smash Bros. Wii U/3DS/@comment-3970120-20130812050526/@comment-25466298-20130812051552

For Amy, the Up Special was originally gonna be the Hammer Jump from Sonic Adventure but I thought it wouldn't work to well in the air. I change it if you want?

For Knuckles, he does have the Gliding ability. It just need to tilt the control stick up twice.

For Shadow, it's his Chaos Burst from Sonic Battle.