Ivan is a considerably young member of Isaac's group in Golden Sun at the age of 15. He is a wind (Jupiter) adept who is capable of controlling wind and electric type Psynergy, not to mention the fact that he can read others' minds, which you can use to your advantage when trying to learn particular secrets. Not only this, but he's also capable of reading non-human minds as well, and learn even more secrets through doing this.
During the events in the game, Ivan isn't too sure of what events took place in his past. Knowing nothing of his parents, he lived in Kalay for years with a man named Hammet. It was foretold through a prophecy known by a select few in Kalay that Ivan would one day join forces with Isaac so that they would then be able to climb the Jupiter Lighthouse. This prophecy came true through the in-game events, and Ivan would then join your party as a playable character.