Complex sentence: When Shift is thrown into the stable, Tash devours him with a frightened Rishda hastily attempting to save himself by offering the remaining Narnians as sacrifices to Tash.
Split into simpler sentences: When Shift is thrown into the stable, Tash devours him. Rishda takes fright at this, and hastily attempts to save himself by offering the remaining Narnians as sacrifices to Tash.