Jenos should be higher in weakness list his relativity ability with his atral mark at max can out heal skye's base damage (unless she poison darts you then your screwed), and his void ability destroys her mobility allowing people to hit her.
Place one illusion behind Evie if you can, keep shooting her, till either she leaves or you get low, on low health teleport to the illusion, keep shooting her, it will give your allies time to get to you.
After she hits a successful ult and eats someone, she'll be vulnerable during her eating animation for a good 2 to 3 seconds. This time is more than enough to burst her down as she won't be able to use any of her abilities during this animation