Izzet charm

[median]

Hey if someone is countering my spell with izzet charm can I use misdirection on it to kill one of their creatures instead?

[quicksilvervii]

Hey if someone is countering my spell with izzet charm can I use misdirection on it to kill one of their creatures instead?

I do not believe so, the mode is already chosen when the spell is played.

While the spell is on the stack, treat it as though its only text is the chosen mode. The other two modes are treated as though they don't exist. You don't choose targets for those modes.
If this spell is copied, the copy will have the same mode as the original.

[Blue Lotus]

I do not believe so, the mode is already chosen when the spell is played.

This is correct

[Clariax]

You cannot change targets of a spell unless something specifically allows you to.  (Which is what Misdirection does, of course.)  You also cannot change modes, or any other choices made when the spell was cast unless something specifically allows you to.  Misdirection doesn't give you the option to change the mode, so the mode remains as it is.

[hvndr3d y34r h3x]

Is this bad boy legal right now in vintage, since it was printed in the V.S. deck, similar to how Hellkite Overlord was legal before the set he was released in cam out?

[bactgudz]

Is this bad boy legal right now in vintage, since it was printed in the V.S. deck, similar to how Hellkite Overlord was legal before the set he was released in cam out?

yes
http://www.wizards.com/Magic/Magazine/Article.aspx?x=judge/resources/sfrvintage
"Cards from expansions and special sets (like From the Vault, Magic: The Gathering - Commander, Duel Decks, etc) are legal in the Vintage format on the date of release of the expansion or special set."