I think (from the left being the most important and right not) : Heavy, Sniper, Back up, Primary, Special, and Melee.
My loadout is
Excalibur, Exterminator, Elder Force Saber, Dark Void Rifle, Prototype S, and Royal Ashbringer. P.S. I'm a 3 cat spammer.
Mine is dark mage wand,orange killer,thunderer,poison darts, and black hole(why doesn't the black hole have grab force)
What do you think?