Nyx Assassin

Nyx is a fairly weak laner. Focus on creep equilibrium, pulling and securing runes for midlaner.

Use Impale to secure the ranged creep and stun opponents at the same time if possible.

Consider hijacking a second opponents' creepwave behind the tower at 50 seconds into the game.

You can use Spiked Carapace during Vendetta without exiting it.

Once you have Vendetta up, be active - setup kills and scout. Avoid showing yourself on the lanes too much.

Pick up Aghanim's Scepter as it improves most of your spells among other things.

Remember to use Mind Flare only after you have used all your other damage dealing spells and items.

Use portals to roam between lanes and get kills with your Impale and Carapace setup.

Be careful not to use a major damaging spell when Spiked Carapace is on or Nyx Assassin is about to use it.

To see Nyx under Vendetta buy Sentries and Observer Wards.

Carry detection on multiple heroes.

Spell immunity is great against Nyx.

Avoid buying too many intelligence giving items against Nyx Assassins Mind Flare.