I originally thought it was Our Lady Peace since the groups seem to have a similar sound but by some digging online I found out the answer. It is a group (never heard of them!) called Stereo Fuse and the song is called 'Superhero' I included the link to their website below which talks about the Medallion preview.
: Does anyone know what the theme song from this movie is. it goes som,ething like this ' i wanna be a superhero, i wanna fly so high'.