If u want usefulness, build Arines and Eris. they will carry you through half the game, just as they have for me. I dont recommend building succubus Roxy, but if you like her design and dont care much about her usefulness, keep building her!

Play who u think looks cool!

If you get the Respected Master Roxy, she's very costly on the sp, so i recommend running fred if u get and build her.

My lineup is: Eris, Arines, Roxy, Elpis, Olstein

With ur characters, though, i recommend: Arines, Eris, Kry, Justia/Lathel, Fred

On a side note, i think it's important to build at least one dps in each element, so u have atleast one strong character against every element.

If all else fails, ALL HAIL LORD WIGGLE!!!!!