Guardian Diaries- Book 4- Siege of the Soul

Every path they have walked, every trial they have faced and every sacrifice they have made, has been to prepare Gallardo and Harry for the final battle. The showdown at Hogwarts, against Diablus and Voldemort. But Gallardo realises that the real battle is taking place within his soul. Without this victory, all could be lost. Gallardo/Marcena pairing, some Ron/Hermione.