Lawrence III/Jirarudan

After findind an Ancient Myuu card years ago, Jirarudan decided to become a Collector.  Using his vast fortune, Jirarudan built a flying fortress to catch the God of Flames (Fire), the God of Thunder (Thunder), and the God of Freezing (Freezer).  According to a legend he's heard, capturing the three pokemon will reveal the God of the Sea, Lugia, a truly rare pokemon who any Collector would want.  Jirarudan goes from island to island, capturing the pokemon, all the while not caring about the negative consequences his actions have on the environment.    Jirarudan is a man who enjoys the finest things in life and is always careful to use proper etiquette.

Melody/Furuura

Furuura is a Miko, a person who acts as a communicator between the gods and the humans.  She uses her orcarina to play the song which calms the gods' anger, which, along with the three treasures, helps to calm the gods' wrath.  When she's not performing some ceremony, Furuura has fun teasing Kasumi, asking whether she's Satoshi's sister or girlfriend. 

Maren/Michiko

Michiko serves as Satoshi-tachi's guide on their initial boat trip to Arshia Island and pilots the boat Satoshi-tachi ride.  She doesn't really do much of anything else.

Lugia/Lugia

Japanese VA:  Yamadera Kouichi

Lugia is a super-pokemon featured in the second movie.  Lugia appears when the three birds are fighting, but it seems calmer and more in control of itself than the birds.  Lugia takes a liking to Satoshi and decides to help him out.  The legendary pokemon can speak human language, swim, fly, and shoot ice. 

Slowking/Yadoking

Yadoking is the evolved form of Yadoran.  Yadoking is able to speak human language, telling the legend of the three birds.  It spends most of the movie worrying in the background.

Articuno, Zapdos, and Moltres/Freezer, Thunder, and Fire

The three mythical bird pokemon are what the majority of the second film centers around.  Freezer is the bird of freezing, and is an ice/bird type.  Fire is a fire/bird type, and Thunder is an electric/bird type.  The birds are also known (at least in the Japanese version) as the God of Freezing, the God of Flames, and the God of Thunder.  When one is captured, the other two become wrestless.  They lose control of their powers and cause destruction wherever they go.  I suppose that when the gods were created, their respective orbs were also created for each bird to ensure that, should the Earth ever become unbalanced, there would still be hope.  Such an event occurs, and it's up to Satoshi to restore balance to the world.