So the ritual worked, the Bard lost his body and became the shadow dragon. They battle stone demons and win.
Unfortunately the Bard failed to inform the Druid of his transformation. So the Druid, in the form of a Demonic Stone Catfish, summons elemental fire in its maw and blasts the shadow dragon like a furnace, killing it.
That compendium class didn’t last long. Once again the Druid is the most dangerous thing the players have ever met.
And the Bard is still not dead. Now he is a living shadow.