Rinoa=Selphie theory

[Serapy]

Clearly Selphie is a sorceress and somehow no one knows it. She stays happy go lucky and allows her diary to be read to give an air of having nothing to hide. But on her trabia computer there is more alluding to that possibly, leading her to corrupt it. The End and other limit break stuff is just a hint towards that. Perhaps it's kinda random like that because she can't control her magic well due to the hiding of it.

Selphie is actually Hyne.

There are lots of possibilities.

Ironic.

Selphie can use any REGULAR / special magic from her limit break without junctioning any GF and without any drawn magic (nothing) !
Rinoa can't even use her limit break (Angel Wing) if she has no magic junctioned. Well, I'm now more convinced that Selphie limit ability actually belonged to Rinoa...

Also, forgot to mention this:
Edea's limit break name shows "Sorcery"

Edit: Quistis can use blue magic (not normal magic though, it's similar to 'Enemy Skill' materia from FF7) without junctioning as well.

Although all of this is a bit contradicting because casting magic is impossible without the help of Dr Odine's tool (para-magic) or GF both for humans, but then again Limit Break completely ignores this fact (except in Rinoa's case, it seems)