Quote Originally Posted by Morgan le Fay View Post
Easy. Take off the rune (from the hero slot) you want to level up and place it in one of the 12 open spots. Buy 11 Synergia and hit combine all. Instant exp boost.

Rinse, was and repeat until your're done and replace the rune back on the hero.
That works? *lol* Y'know, I thought about trying it, but just never did. cool! (I think there are 20 spots, btw.)