Not having read the 'Black Summer Graphic Novel', I can only speculate. There could be a group of survivors as main characters. Maybe a protagonist who is on a quest to find their lost family during this 'black summer'. There might also be a character who is a bit of an outcast but has some special skills that are crucial for the group's survival. Another character could be a scientist or someone with knowledge about what caused this 'black summer' in the first place, and they are trying to find a solution while also dealing with their own personal struggles.
Since I haven't read the 'Black Summer Graphic Novel', it's hard to say for sure. However, in a story like this, the main characters might include a brave leader figure who tries to bring order in the chaos of the 'black summer'. There could also be a young and resourceful character who discovers new ways to survive. And perhaps an older, wiser character who has some knowledge from the past that can help the group get through the tough times.