When you are outside of stealth detection range but within the Retribution range, the insignia will still appear above Skye even though she is invisible. Shoot below it for expected results.

Try to re-roll Retribution as often as you can until you can see Skye. Then you have an incredible advantage and should dominate her easily.

Use Retribution to exclusively target Skye. With Discover, your entire team will be able to see Skye coming from a mile away. Combine with the item Keen Sights for added visibility

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.

Skye will lose if up against Lex. Make sure you either have the last pick, or make a team member pick Lex, so that you remove the risk of facing him in competitive.

In a general way, avoid character who is able to do big damage in a single shot, you will often loose unless they are already low.