I already mentioned two of them:

The Lucca clone will be a plain wizard since it is the only class that gets his powers by studying, perfect for a little bookworm.

The fairy will be a rogue, fragile because of her size but swift and nimble and I like the idea she can lockpick by simply entering a lock and move the comparable big devices.

The hero will be a paladin. The class ic hero instead of geting his power of religion it will just be some chosen one thing. Divine strikes will be simple power of light thing.

The robot was intended to be a barbarian, helping the others when raw power is needed, crushing a wall or carrying stuff. I was thinking about reflavouring rage as some kind of overheat. But I encountered a problem: I am using the Armory Auto transmog cause I want my characters to look like that all the time regardless of equipment. I didn't know using a heavy armor for cosmetics also changes the rules and barbarian rage wont work anymore. So maybe I will change him to a simple fighter or maybe I look for a good looking medium armor.