NS is a pub hero, so I really don't know what the big deal is when you consider how he needs to wait until night to be somewhat of a threat. And the fact that it is 3v3 makes it even easier to know when NS is going to try ganking.
Butch T. Cougar thinks you should ...
Check out my hero suggestion.
Goliath the Guardian Golem
His Overpowered in night!!
No one can touch him at night!!
Balanar grants :
4 sec slow spell
8 sec silence spell
40% to miss an attack spell
What more do you need than above thing??
Just dont stay close to him on night!!
As previously stated here, you need either a lane control hero or a harasser to dominate him early game. Personally, I've found Huskar can be extremely effective for doing it. Just burning spear his butt off.
I guess a short list of heroes to counter NS. I guess Axe is the biggest problem because even when he is low in hp it takes alot to kill him. Also if he gets NS low enough he could die.. I think Lycan isnt so bad because his wolves will destroy a lane with NS and if he gets to level 6 he can run away from him. I think Syllabear is a good counter how you can do anything about his bear and hes probably just as annoying as NS early game.
I was thinking about Panda how he also has a slow and spell that slows and misses. He can also ult if hes low so either you dont die or you see if NS stays around and might get a kill. Im just not sure if he waits till your ult is over to attack you but hopefully you hurt him enough that he doesnt stick around. I think if your good with Bristle he might be able to tank whatever NS throws at him but i wouldnt push too far because you need to stay close to tower at night to be sure.
I think Enchant could be good because of your heal and untouchable but hes pretty low on hp but still would do alot better in a lane then NS. I think Batrider could be good because he has good stats early on and he cant chase you with Firefly which you should be able to use after you tank whatever damage he does. Necro'lic/Visage is also pretty good because all your revenants will be attacking him while he chases you. You would just need some hp items early on because his hp is pretty low. Dark Seer would be a pretty fun hero how he can hopefully save anyone that NS is chasing with surge as well as have a strong lane.
I see the main problem vs NS is having low starting hp because he can just nuke/wack/nuke and ur dead. Hes still tough but as long as you dont die right away to his combo you can end up probably surviving whatever he does. He also isnt that good of a pusher until night so you will have the ability to tower hug to help with his attacks.
If NS solo, you should pick someone to lane control the crap out of him. If he go to dual lane he wouldn't be at sufficient level by first night.
If you are playing EM I suggests you pick NS first because he is the best hero at EM mode,