Legend of the Guardian
"Disturb not the harmony of Fire, Ice, or Lightning, Lest these Titans wreak destruction upon the world in which they clash. Though the water's Great Guardian shall arise to quell the fighting, Alone its song will fail. Thus the Earth shall turn to Ash. O, Chosen One, into thine hands bring together all three. Their treasures combined, tame the beast of the sea. From the trio of islands, ancient spheres shall you take, For between life and death, o the diff'rence you'll make. O, Chosen One, climb to the shrine to right what is wrong, And the world will be healed by the Guardian's song."
The Legend of the Guardian mostly features Lugia but the three Legendary birds also play a part. Each of the Legendary bird's orb like treasures that are called ancient spheres holds a secret to calming them down since Lawrence III, a Pokemon collector, disturbed their harmony by trying to capture all three to summon the Guardian of the Sea, Lugia and capture him. By doing this, the world started to get plunged into chaos. He succeeded in capturing Moltres and Zapdos, but his plains where fouled by Ash and friends. The three ancient spheres reunited the harmony to the Legendary birds, the Beast of the Sea, but most importantly the entire world. It's up to the chosen one, which this time is Ash, to get all of the trio of islands ancient spheres and place the treasures up to the shrine to stop the disturbance and to keep the world from being destroyed. Then Melody plays the song, reviving Lugia again from the depths of the ocean.