So the latest session of the now-epic D&D 3.5 campaign ended last night with the BBEG going down in a ball of fire, detonating in a blast no one could survive. The fight before the fire-works lasted well over an hour in real life, and had her going One-winged angel, twice.

Normally, I'd consider going up in an explosion big enough to wipe off a mountain-top a proper way to exit for any villian, but this gal has essentialy been the driving force behind the plot for about 26 levels, and because of the fact that, she was never intended to be the unredeemable, omnicidal, puppy-kicking nutjob who has no moral-qualms turning every living being on the prime material plane into an incubator.

Also, the player never really learned much of her motives, which I intend to explain as the true evil behind her is revealed. This brings me to my dilemma, I wish to portray her as having fallen in love with the real villian, with the real villian simply having played along, using her to furthen his own schemes. I need to have the real villain get rid of her(preferably while mentioning about having outlived her usefullness), and really just seal the deal that, while there may have been some redeeming qualities to this previous villians, this new villian has nothing good to say about, no redeeming qualities, no soft spot for baby penguins, no nothing.

So, I was hoping some ideas, on how should I do this?