One of the most interesting things that the Wally West Flash series did was the the Rogues, the loose assortments of villains that had plagued Barry for years,
and retconning them as... well, a sort of family, a dysfunctional family but they a bond between them. Originally they had little in common with each other, other than they bought their costumes in the same place and were united in their hatred for the Flash.
I'm still preparing my Serpent Society history post, but I found this in my LJ gallery lelarly having intended to post it at some point, but I don't think I ever did, so here is another take on villainous relationships, before it became somewhat friendlier, for a given value of friendship of course, as via cary bates and Carmine Infantino, we find out how the Rogues originally handled the death of "one of their own"
( Remember, these are NOT healthy people )