Free Agent - NA
I have never liked debilitate. To expand, it is really good and very effective at its job, but it isn't for me. Something just felt off about it for me. So, I created a Smoke and Dagger build instead. This playstyle still focuses around being a pain in the ass and killing the backline super quickly, but it also gives the opportunity to provide a tiny bit of support for your team that can push you through a fight. Also, if you never noticed, Skye builds her ultimate really quickly. It isn't hard to get 4-5 ults per game. The combo of poison, in-hand, and healing skyerockets (lol) your ultimate generation ability, even without morale boost.
Always try to be the annoying flanker first. The enemy team will almost never buy illuminate first. If they do, then just keep in mind who bought it and give them a slightly wider berth than you normally would (learning how far out illuminate reveals is a must for Skye mains and one tricks). You are still a flank, only if you are really being countered should you switch over to mainly supporting your tanks or healers in their fights. Skye can work wonders as a counter against flankers, sitting silently beside her supports and then revealing herself only once the flank has dived in.
One of my favorite tricks is only possible if the enemy team doesn't have illuminate or big blast damage, but you can stay invisible for very long periods of time by using smoke bomb, sitting there until it runs out, then using hidden, then smoke bomb again, and then a smoke bomb reset with your poison bolts can extend it even longer. This is really effective for contesting objectives for up to 15-20 seconds. Always remember that smoke bomb is a stealth ability, and while it is only in a small area, it is constant. Smoke bomb should be used as your main source of invisibility.
(Also, this is the build I always use. You can look at my profile to see how I'm doing with it. 30 levels on Skye and going strong.)
Edit: I have begun using debilitate now, but I still use the same build and logic to my flanking. Definitely prefer smoke and dagger, but debilitate works with the build too! (also some grammar updates, I must have been tired when writing this)
Poisoner
Poison Bolts
Reduce the Cooldown of Poison Bolts by 3.2s.
Level 4
Confound
Poison Bolts
Reduce the Cooldown of Smoke Screen by 2s for each enemy hit by Poison Bolts.
Level 4
Decrepify
Poison Bolts
You do not consume Ammo for 0.5s after hitting an enemy with Poison Bolts.
Level 1
Quick Smoker
Smoke Screen
Reduce the Cooldown of Smoke Screen by 1.2s.
Level 2
Healing Vapors
Smoke Screen
Heal for 500 over 2s while in Smoke Screen.
Level 4
Smoke and Dagger
Smoke Screen
Benefits from your Smoke Screen cards also benefit allies who enter Smoke Screen and allies are Healed for 100 every 1s while in your Smoke Screen, but Smoke Screen no longer applies Stealth to you.
Level 1
Level 1
Nimble
Armor
Gain 7% Movement Speed.
Level 1
Resilience
Armor
Reduce the duration and effectiveness of Crowd Control and Slows by 25%.