10 Things DC Comics Wants You To Forget About Ra's Al Ghul
6. He Poisoned Kingpin's Wife
Though they may seem like pretty bitter rivals now, Marvel and DC used to be on amicable enough terms that their universes would occasionally cross over. One such crossover was Batman & Spider-Man: New Age Dawning.
In the story, Ra's al Ghul planned to wipe out New York City by sinking it under the ocean. As part of the plan, he gave Kingpin's wife cancer and forced Fisk to work with him in exchange for a cure.
Kingpin then almost immediately betrayed Ra's because cancer is not a great tool for keeping a workforce motivated. Fisk helped Spider-Man and Batman sneak aboard his plane so that they could stop Ra's' plan and save the city.
Defeated, Ra's left. Before he went though, he told Fisk that he had lied about ever having a cure for cancer. However, it turned out Ra's was just continuing his trend of trying to ruin people's lives for fun and later Talia handed the actual cure over to the heroes.
Sadly, with Marvel and DC now wrapped up in much larger and competitive companies, these kinds of friendly crossovers seem unlikely to happen again and DC would probably rather you forget they ever existed. Although, they're nothing compared to the next entry.