Bowser Jr.

[Rökkan]

Okay then, other examples:
Ness and Lucas, both as far as I know, doesn't have any of those techniques they use as B attacks, none of their PSI/PK powers are offensive, just defensive and healing spells (therefore, they don't have PK Flash, PK Fire, PK Freeze and PK Thunder). And we all know that PK Starstorm is a technique from Poo and not Ness.
(but Earthbound fans feel free to correct my statement!)

Meta-Knight's entire moveset is based upon Kirby's abilities. Mach Tornado controls exactly like Kirby's Tornado ability, Meta-Knight's Up+B is from an attack from Kirby's Wing ability, Meta-Knight's normal attacks are from Kirby's Sword ability, and Meta-Knight's grab attacks are from Kirby's Suplex and Ninja abilities.

Now, I suggest that we use techniques derived from his brothers, not only as references to the series, that most charaters do have in their moveset, but also to create some variation on his attacks. Think about it, if we just base on Bowser Jr, pretty much the vast majority of his attacks will be about spilling rainbow-coloured blobs of ink, even though he has the Sonic Roar, and in NSMBWii, a smaller and cuter version of Bowser's Clown Car. It just doesn't really sound like a cool character to play as.