I approve, although I would probably go flash exhaust instead, but that's minor stuff that you can decide on.
Build is fine, I approve of a beefy Nocturne. Only thing I recommend is trying to find a different mastery set up, but, as with summoner spells, it's subjective. 21 into offense is wasted in my opinion, as things stop being useful once you hit the armor pen/magic pen in offense. I would rather invest more points into utility for the buff durations and mp regen.
Looks good to me, and yes like the guy above me said flash exhaust seems to be better. Stops people from flashing out of your fear. since dusk trail is an mspd steriod. --- I'll be a Pauper: reverent in dereliction I'll stand a Shadow: bear witness to the atrophy
Should get Cloth Armor or Long Sword + Health Potion instead of Doran items to build into Wriggle's Lantern so you always have a ward on the map which you can use to gank people alone that you know you'll win 1v1.
Havoc's been mired in mystery since it's been made. The end result being the conclusion: It does not, in fact, increase ALL damage by 4%. As a matter of fact, it seems to be quite selective in what it DOES increase, and appears to be an on-hit effect for physical abilities, and have little effect on spells.
So it'll benefit auto attacks and some abilities, but not all.
16/0/14 is a great talent set up for a Melee DPS though.