Originally Posted by Silvermoth
Can marvel use madam hydra? I thought she might have gotten snapped up by fox
They can use Madam Hydra. I think Feige himself might have confirmed that they could use Madam Hydra but not the Viper persona. It might have been someone else who said that but I'm pretty sure one of the filmmakers said she's still viable. Seeing as Quicksilver is in both DoFP and AoU, I don't see why they couldn't use the Viper persona if they really wanted to. If I'm not mistaken she took on the Viper name after killing the original serpent squad member
in a Cap story. The only real difference that I can detect is the name change though. Visually and design wise she's the same character and essentially a prototype for Sin.