Viper
Fans of Marvel Comics may know this, but one of the characters to go by Madame Hydra also went by Viper. It wasn’t just because she’s a deadly assassin; no, she can literally be poisonous to people. And those poisons are powerful enough to affect healing factors. She once held Sabretooth prisoner (Death of Wolverine issue No. 2). During that time as long as Sabretooth was, as she said, a “good doggie” he got the antidote. If he wasn’t, he would have been killed. It further shows how ruthless and dangerous she is. Which leads us to where she’s done her worst.
Ruled Madripoor
Madripoor has had more than its share of rulers. Most of them were vile human beings who preyed on the misfortune and greed of others. None of them were as evil and, for some reason, as beloved by people as Madame Hydra.
Madame Hydra would allow anything as long as she could get something out of it. It wasn’t always money she was after. Since she had eyes and ears all over Lowtown, she could get information. That info usually led to her blackmailing people and calling in favors down the line.
If it benefits Madame Hydra, she lets it happen. If it doesn’t, she shuts it down and will likely kill whoever didn’t cut her in on what they made.