It has more recently been pointed out to me that, contrary to my initial assumptions, Girafarig’s Pokédex entry on Crystal version seems to imply it’s her auxiliary rear head that is responsible for her psychic powers, not her main head – so maybe flip those two around, with the ‘power’ form referring to the dominant giraffe head. That minor point aside, though, I think I like the basic idea, because it expresses the uniqueness of how her bifurcated nature affects her fighting style much more clearly than anything she’s got at the moment. I would point out that, assuming you intend this to work more or less like Aegislash’s stances, you are effectively giving Girafarig a no-questions-asked +30% to both attack stats, and I’m not sure whether that’s exactly what you intended. Depending on exactly how you choose to do her effort training, this translates into an effective increase from 80 base attack and 90 base special attack (which is nothing special) to about 118 base attack and 132 special attack (which is f&%#ing terrifying). Having said that, she’s still pretty fragile and not all that fast (though she does get Agility), doesn’t have any really powerful attacks, and is saddled with a rather poor offensive type combination, so I don’t think we’re necessarily looking at broken levels of power here – just dangerous.
Myself, I think I might go with something other than plain bonuses to different stats for the two forms – keep the switching mechanism, where physical moves shift her into ‘power’ stance and special ones shift her into ‘mind’ stance, but maybe make the benefits things that emphasise the way the two work together? Maybe ending her turn in one stance boosts the attack stat associated with the other, for instance? As long as she’s in ‘power’ stance, her second head is constantly storing energy, while as long as she’s in ‘mind’ stance, her main head is building up its own focus. Something like that might be more interesting.
Pokémaniacal 