>>96075700
Before getting into characters, you should settle on a campaign/scenario first. Do you want the characters to be part of Infinity Patrol/Interworld, are they some separate group that's engaged in intradimensional travel, did they get hit by a Banestorm and wind up stranded in another universe? Was an entire city/region dislocated by a Banestorm? Did they stumble upon some kind of stable interworld gateway? What kind of world did they come from, and where did they end up? Start with the concept, and characters will flow naturally downstream.