Questions about the gameplay of Heroes 6.

Hello everyone.
I just wanted to ask one thing: is it possible to change the champion in the "Skirmish" game mode without connecting to the Conflux? I really don't like Lorelei, and I'd like to choose a different hero as the starting one, but I couldn't find any button that would allow me to do that.

If it's not possible to change the hero, maybe at least change their portrait? That would be better.