The Coliseum is where you battle and train against other wizards and pets.
The coliseum is a place where you battle against AI wizards. These wizards have pets that will help them during the battle. Keep in mind that the pets can be 1-4 and can be any pet in the entire island of Prodigy. The wizards can have up to 4 pets, so keep that in mind as well (All the wizards except Gina, of course!).
The levels are these wizards are in a certain order. You can battle some opponents right away. But some you need to wait until you are leveled up to even face them. Keep in mind that depending on the level can also automatically grant them new spells. For example, Gina is level 10-20, and Crios is level 100. Crios can use Zero, Powerbeam, Pummel, Conjure, Batter up!, and Magi-shot. Gina can use Conjure, Batter Up!, and Magi-shot.
How to beat the wizards
It's simple. To beat the wizards you first need to know what element their pets are. You can tell this by before you battle them. It will show you the wizard and a picture of their pet. Observe the pet and you can predict what element it is. After that assemble a team that will be strong against it. (Fire is strong against Ice and Earth/Plant) Then go to your healer and get you and your pets healed so you can battle with full hearts. After that you can challenge your opponent. It will only show a single pet, though, so take a good guess!
In every battle you will earn a prize. It will be either coins or you can earn clothing which is part of the coliseum set. But you can get other prizes from the chests you get after the battle.
The arena is where the player can battle other people. Winning battles increases your Rank. Your rank can let the player buy clothing along with staffs dependent on your rank. You don't get stars or gold coins, nor clothing, but the higher the rank, the better things you can get!