So, given that you have a choice of what class the Hero will be, who do you usually choose?
Myself, I go for a Psy Fighter in vast majority of cases (along with useful Orb intake, making it a versatile, powerul and highly mobile unit), but have experimented with other class types as well and found that the Assassin is pretty good, especially when backed-up by orbs (effectively killing Shadow Guardians on last map in one go with Mega Stab!).