If Skye is playing against a Lex, it is best to just run away, as she will have little ability to defend herself, and will easily be shredded apart by Lex.
Heroes who have a card that allows them to reveal enemies with weapon shots are extremely strong against Skye. For example, Viktor's Predator card allows him to reveal targets for half a second every time they get hit by Iron Sights.
Viktor can easily penetrate this front liner's shield, and his grenade has a big enough radius to damage anyone behind Barik's shield. Also, Barrage can easily be used as a flank Ultimate like Skye's, and can kill Barik's team if they are close.
Ruckus easily rips through Androxus, and even if he tries to use Reversal, Ruckus can activate his shields to negate any damage fired back at him, and if Androxus tries to escape, Ruckus can easily jet over to him.