Sonic - Fire Souls

[Almo]

hey guys this mite be a stupid question but ive been workin my ass off tryna get fire souls, is there a good reason for this? i mean what do they do?

 

[Let_It_Burn]

I have no idea either... I think they only gives you more XP! might be wrong tho

 

[Almo]

have done some research,apparently they unlock characters to play with in party mode, Also collecting heaps of silver medals unlocks different sonics ( fire,dark and wind) to use!