Jocasta essentially has the same personality as Wasp, as it is her brain patterns and personality that Ultron downloaded into his robot bride. Megan Fox wouldn't be good for the role of Wasp, so she wouldn't be suitable for Jocasta either. The voice of Jocasta should be played by the same actress who plays Wasp in the Avengers, only more robotic. If Autumn Reeser won the role of Wasp, she could do the voice of Jocasta as well, but differentiate her peformances. Megan Fox doesn't have the range to play Jocasta. I imagine Jocasta would be like how Jeri Ryan did Seven of Nine in Star Trek Voyager. She can act and gives a totally different performance in all her other appearances in other shows, but was more cold and emotionless in Voyager. For that sort of role of Jocasta you actually need a half decent actress, otherwise it's like saying that for someone like Spock you should get some actor who can't act because Spock doesn't show emotion.
