well, in the common sense of comic books, the story should probably start with the end first.
so like, at the end of the story, if the city is pretty much destroyed but he still hasn't fought Hades, you could have ares looking around, surveying the damage and what not, thinking to himself, and in the next frame, have him spot, idk, eyes or something out of the shadows, and he could think "there was only one thing left to take care of"...and then bam you start from the beginning.
you get what i'm saying? you'd do a flash-forward in the beginning of the actual comic book, then you'd go back to show what happened in order for the flash-forward to have happened.
so the order would go like this: FLASHFORWARD: Ares sitting surveying damage after battling all the titans. FLASHBACK: beginning of story, Hades bringing people to the underworld, whatever. Ares arrives to battle. Battles the titans. and now you've reached the same point in your flashforward. Now, Ares says "there was just one thing left to take care of" again and he battles Hades. the end.
you get what i'm saying?
i hope you do cause it's kinda hard to explain but i'll try again if you need me to, lolz. 😉