In the 'Seven Kings Must Die Back Story', the seven kings are surely central figures. They could be diverse in personality, some might be benevolent while others cruel. There may be characters like seers who predict their fates or warriors who fight for or against them. There could also be family members of the kings, like queens or princes, who have their own agendas and influence the overall story. And perhaps there are outcasts or rebels who oppose the rule of the kings and contribute to the complex narrative.
I don't know the specific main characters in 'Seven Kings Must Die Back Story' as I haven't read or studied it.