Welcome, I'd like to think that based upon what I've seen this build goes against the norm. I'm fine with that. I've never really been a fan of anti-armor and instead over my time playing with Nova I've come up with this enjoyable build instead.

The basics:

Snipe:
I have a love/hate relationship with this ability. Its your main burst source but at the same time you have to be patient and make sure you line up your shot and hit your target. If you react too fast more often than not you will miss with snipe. Later on its a big deal because Pinning Shot will provide vulnerability damage.

Pinning Shot:
Your bread and butter for this build, its not your main damage source but the crippling slow and the vulnerability that it provides later on will be the mainstay for putting away your opponents.

Hologram:
Its important to understand how stealth heroes work in this game. You are invisible yes, but your character is visible to the keen eye and you can be pulled out of stealth by aoe damage and you have to be aware of this. Most often they will buy the bait and hit your hologram. Best idea is to place your hologram and run backwards from where you place it.

Precision Strike:
I love this ability because it isn't hindered like Triple Tap will be against a team who knows how Nova works. Triple Tap is deniable in many ways. Precision Strike is not if its well timed with an AoE stun or what say you and you can cast it from anywhere on the map, you can also use it against an enemy keep / fort that's almost dead and needs to be finished off. Once upgraded you can stack up to 2 charges and make it worth your while.