Here are the codenames and the rank of each person.

Percy: 

Codename: Omega

Rank: Commander

Team: Elite

Mitsuki:

Codename: Meiyo (Honor in Japanese)

Rank: Commander

Team: Theta

Luke:

Codename: Alpha

Rank: 2nd in command

Team: Elite

Raven:

Codename: Cryaotic

Rank: 2nd in command

Team: Theta

Zoe:

Codename: Fallen

Rank: 3rd in command

Team: Elite

Anna:

Codename: Azalea

Rank: 3rd in command

Team: Theta

Bianca:

Codename: Archangel

Rank: 4th in command

Team: Elite

Souta:

Codename: Yuuki (Japanese for spirit)

Rank: 4th in command

Team: Theta

Bekendorf:

Codename: Forge

Rank: Warrior

Team: Elite

Selina:

Codename: Beauty

Rank: Warrior

Team: Elite

Ethan:

Codename: Balance

Rank: Warrior

Team: Theta

Kalani:

Codename: Dove

Rank: Warrior

Team: Theta